Cressida Bonas: Everyone seems to have very strong opinions about my wedding

White House Farm began last week on ITV; a six-part factual drama about the notorious murders. I play Sheila Caffell, Jeremy Bamber’s sister and one of the victims. She was initially thought to have committed the crimes, and was described in the tabloids as ‘crazed’ and ‘deranged’ — an unfair portrait of a mother who was suffering from schizophrenia. I hope people who see it understand the turmoil she had to go through in life. There’s a lot of talk about mental health these days. Researching the part, it occurred to me that we have as a country become much more understanding on the issue. That’s a good thing. I hope Sheila’s reputation is repaired.

Getting to know Sheila’s ex-husband Colin Caffell, who supported the show, was an honour. It’s remarkable how he has managed to overcome the devastation inflicted upon his family by Jeremy Bamber (played brilliantly by my friend Freddie Fox). Colin’s book, In Search of the Rainbow’s End, is his account of what happened that night and the years of suffering he went through. Every day on set I would carry his book around with me.

I do love Lorraine Kelly. Doing press for White House Farm, I was asked to go on her morning show. I wanted to talk about the work, but I was apprehensive that I would be questioned about my past love life. I usually get asked and always give some awkward answer; the journalist then looks equally uncomfortable as I try to move the conversation on. My mum, who loves the Lorraine show and watches it every morning, said: ‘Don’t worry, Lorraine is lovely, motherly, a kind person, and she won’t ask you anything horrid, I promise.’ I reminded her that she doesn’t actually know Lorraine.