Cressida Bonas has opened up for the first time about the profound heartbreak she endured following the death of her sister, whom she considered a “miracle,” due to cancer. She shared her struggles in dealing with the grief that followed.

The 37-year-old, who is known for her past relationship with Prince Harry, recounted the “shocking” experience of losing Pandora Cooper-Key in July 2024. Pandora was 51 years old and had bravely battled cancer for 26 years.

In a candid interview, Cressida also expressed her deep affection for her husband, Harry Wentworth-Stanley, 36, and touched upon the challenges she faced during her two-year relationship with the Duke of Sussex.

During a conversation on the Therapy Works podcast with psychotherapist Julia Samuel—a close confidante of the late Princess Diana and godmother to Prince George—Cressida shared the emotional toll Pandora’s passing has had on her family.

“For 26 years, cancer was a constant in her life,” Cressida explained. “It would appear, disappear, and then return in different parts of her body. She faced sarcoma and Paget’s disease. Ultimately, she developed an inoperable tumor and passed away. It’s difficult for me to even say the word ‘died.'”

Pandora, known for her work as a ceramicist and her role as a former accessories designer for Vivienne Westwood, was afflicted with Li-Fraumeni syndrome—a rare genetic disorder that hampers the body’s ability to combat cancer. Her initial diagnosis occurred just five weeks after welcoming her eldest son, Bow, who is now 18.

Cressida said: ‘To watch the most important person in your life die is just completely shocking. I don’t think that you’re prepared for that in the Western world. No one tells you about that.’

Despite her prognosis, Pandora repeatedly defied the odds. ‘She was kind of a miracle because people would say, well, you won’t survive – and then she did. For years and years,’ Cressida recalled. ‘And then she’d have years in between of living her life and having kids.’

Prince Harry’s ex-girlfriend Cressida Bonas (right), 37, has described the ‘shocking’ experience of watching Pandora Cooper-Key die in July 2024, aged 51, after a 26-year battle with cancer

Speaking to psychotherapist Julia Samuel – a close friend of the late Princess Diana and godmother to Prince George – on the Therapy Works podcast on Wednesday, Cressida laid bare the grief (the two sisters pictured together in 2016)

Cressida, the youngest of Lady Mary-Gaye Curzon’s five children, added: ‘Doctors said she would die by the end of today, and then she didn’t, or she would die tomorrow, and she didn’t.

‘It just went on and on. That sounds quite a brutal thing to say but we really wanted her to let go because it was so painful to see her in this pain.’

Cressida married property investor Harry Wentworth-Stanley in 2020 and they have two children – son Wilbur, three, and daughter Delphina, eight months. The sisters’ bond was so deep that Cressida gave her daughter the middle name ‘Pandora’ in tribute when she was born in June last year.

During the podcast, Cressida also told how she wrote a letter to Pandora in her final days and read it to her while she was unconscious.

‘I said everything I wanted to say, which was thank you so much for being my big sister and being another mother to me and being my friend and loving me the way you loved me,’ she revealed.

She admitted it was incredibly difficult to show her emotions in front of Pandora. ‘I took her to one of her last appointments. The doctor was talking to her, and she didn’t even have to say anything – I just knew in her eyes that she couldn’t do anything… that it was time. I pushed the chair behind my sister – we were sitting next to each other – because I was crying. I didn’t want to see Pandora see my tears because I wanted to be strong for her. She wasn’t crying. I thought, I have to be strong for her.’

She continued: ‘A week later, we were having a coffee, and she suddenly said, I don’t understand why none of you are crying. And I said, oh, my gosh, we cry all the time. We just don’t want you to see our tears, but we cry all the time.

‘She said, “Please don’t hide your tears. You have to be truthful with me as I am truthful with you and we have to be in this together”.’

Pandora, a ceramicist and former accessories designer for Vivienne Westwood , suffered from Li-Fraumeni syndrome – a rare genetic condition that prevents the body from fighting off cancer. Pictured: Cressida and Pandora 

Cressida (right) confessed that she has struggled to sit still since her sister’s (left) death. ‘I had this kind of engine and this adrenaline to just keep busy,’ she said

The actress admitted that her grief has been far more complex than she anticipated – and that numbness is harder to bear than tears. ‘I thought that the grieving process would be one continuous line of sadness, but it hasn’t been that. It’s been all sorts of different feelings and emotions and it’s not what I expected,’ she said.

‘The days that I cry, I feel more connected to her and I feel more connected to myself and I feel more connected to something. And it’s the same when I feel joy, and it’s the same when I remember the wonderful memories I have with her.

‘The worst days for me are the days when I feel nothing, when I feel numb… Those numb days for me, I don’t feel close to her. When I cry and I feel joy thinking about her, then I feel closer to her.’

Cressida confessed that she has struggled to sit still since her sister’s death. ‘I had this kind of engine and this adrenaline to just keep busy,’ she said. ‘Is there a right way to grieve? I don’t know. But I know from what I read that that’s probably not the best way to go about it, and you should maybe just sit with those feelings, but I couldn’t. Even now, sitting still is still quite hard for me.’

She added: ‘I just miss her so much, and I just want to ring her and I want to say, what do I do about this? Or what do you think I should do about this?’

Cressida shared that the weekly breakfasts the five siblings used to share with their mother have stopped since Pandora died. ‘My mum has five children and Pandora’s the oldest and I’m the youngest within that. We always had breakfast every week,’ she explained. ‘We tried to find that time just for an hour to see each other.

‘And then after she died we haven’t done it. I hope we will but at the moment it feels just too painful. I think my mum really wants that to happen, she’s desperate for us to do that again and we will.’

Cressida added that being a mother herself, she cannot comprehend the grief over losing a child. ‘It is completely unimaginable to me. I can’t even begin to imagine that,’ she said, adding she has also learned to appreciate the smaller joys in life through her grief.

Despite her prognosis, Pandora (pictured) repeatedly defied the odds. ‘She was kind of a miracle because people would say, well, you won’t survive – and then she did. For years and years,’ Cressida recalled

Pictured: Cressida (right) arrives at Pandora’s memorial service in September 2024. The service was attended by Queen Camilla’s son Tom Parker Bowles and her nephew Sir Ben Elliot

‘Those tiny moments that we often take for granted or we overlook, she was so grateful for. I think that’s been really formative for me because I find myself being more aware of that now,’ she said. ‘Seeing the beauty in the very ordinary moments is definitely from her.’

She continued: ‘Sometimes I go into my little boy’s room, and I lie next to him just for ten minutes before I go into my bed – just to listen to him breathe. He’s normally such a deep sleeper, but the other night he stirred and he woke and he put his little chubby hand on my face and said, I love you, Mama. And just that moment, I thought, is gold.’

Cressida also spoke candidly about some of her struggles during her relationship with Prince Harry, who she dated from 2012 to 2014 after being introduced by Princess Eugenie.

Despite attending the Duke’s wedding to Meghan Markle in 2018 and remaining on good terms with the Royal Family, she said being defined by the relationship has been challenging.

‘It’s frustrating to sometimes be put in a box of privilege and my past relationships,’ she said. ‘I’m more than aware of the privilege that I come from. But to be put in a box is incredibly limiting.’

Her brother-in-law Sam Branson – husband of her half-sister Isabella Calthorpe and son of Sir Richard Branson – once gave her blunt advice when she was upset about being talked about publicly. ‘I was really upset one time because I read something, and he said, quite brutally: “It’s none of your business. You can’t control it. What are you going to do, ring them and say, hang on? You can’t. So there’s no point really”.’

She also revealed that some of those same frustrations and projections followed her into her acting career.

Recalling her audition for the ITV drama White House Farm, in which she played real-life murder victim Sheila Caffell opposite Stephen Graham and Freddie Fox, she said: ‘I went into the audition, I thought, there’s no way I’m going to get this because I don’t have really dark hair and they’re going to just see me as a posh blonde… But I really would love to do this part. So I just went for it. And the director saw past all of that and he just looked at my acting.’

Cressida also spoke candidly about some of her struggles during her relationship with Prince Harry, who she dated from 2012 to 2014 after being introduced by Princess Eugenie. Pictured: Cressida at Meghan and Harry’s wedding in 2018

Cressida (pictured) revealed she has stepped back from acting since becoming a mother, but remains passionate about creativity

Cressida revealed she has stepped back from acting since becoming a mother, but remains passionate about creativity.

‘Watching Pandora die in hospital was so humbling because you realise life is so precious and we don’t really have long, so what do we really want to do?’ she said. ‘I am a really creative person and all I want to do is create… Acting is also a way of expressing things that perhaps I struggle to express day to day, like anger.’

She continued: ‘Through Pandora’s death and having children, getting older, and knowing what I know and all the experiences I’ve had, I really don’t want to waste time sweating the small stuff – which I do, but I really am aware of it more than I used to be.

‘In my 20s I was looking to the future a lot, thinking, what next? I was also nervous about if I’m going to say the wrong thing and I’m going to be judged. Whereas now I’m like, god, get over yourself.’

She added: ‘Since having children, I think I’ve found more confidence – being a mum. That being said, it’s incredibly challenging, and it challenges me every single day and tests me every single day. But I have found more confidence.’

Speaking about her husband, who she rekindled a romance with after they first dated at Leeds University, Cressida added: ‘I have a husband who I adore, who I feel like I must have done something pretty great in my last life to end up with him, honestly.’

The couple married in a small lockdown ceremony at Cowdray Park in West Sussex in July 2020, with just 30 guests present due to Covid-19 restrictions.

Pandora, who was mother to sons Bow and Nestor, 15, from her marriage to therapist Matthew Mervyn-Jones, was remembered at a memorial service at St Luke’s Church in Chelsea in September 2024.

Cressida read a moving letter she had composed after her sister’s death, telling mourners: ‘My heart is forever tied to yours.’ Their mother Lady Mary-Gaye, 78, paid tribute, saying: ‘Nobody on earth who ever met Pandora could help falling in love with her.’

The service was attended by Queen Camilla’s son Tom Parker Bowles and her nephew Sir Ben Elliot.

Pandora’s father, aristocrat Esmond Cooper-Key died of a brain tumour in 1985 aged 42.