My mum has been sacked for misconduct

My parents are moving across the country to live closer to me and my partner and everything was going well. My mum was offered a job at the hospital here doing the same clerical job as she has been doing for 11 years now. She handed in her notice for her old job last week and had two months notice to work. However, I rang her today and she told me that she has been dismissed for misconduct (it was a data breach - she looked at something she shouldn’t have). She really regrets it and said she had a reasons. I’ve take the line that she made a mistake and that she needs to stop beating herself up about it and look to he future. It came as a big shock obviously and she’s very ashamed and upset as this places a lot of pressure on my dad. He is telling her to tell the new employer straight away that she has lost her job, but I advised talking to the union first. Does anyone have any input on the best thing for her to do? We all assume if she tells the new people they’ll definitely withdraw their offer...I suppose I want to know if there any any serious repercussions to her not telling them and then finding out later. I’m very worried about this and it’s hard seeing her so upset and I think this whole thing has come as a shock to all of us. I can’t speak to many people about it as obviously she doesn’t want many people to know. She seems to think that because she is 60 and was sacked, no one will ever take her on again (as I said, she had this job for 11 years and has never done anything like what she did before). She thinks she will be unemployed forever meaning they will have to downscale their house etc. Any advice welcome, but please no judgement on what she did. We all know it was bad.

I think she should just apply for a new job. If she is asked she should (with the disclaimer of deeply being ashamed and regretting it very much) tell her new employee what she has done. However only if the new employee asks. However this may vary from country to country and from what is acceptable there. Generally speaking: when someone admits and is open about their past failures and openly repents what he has done I personally take that as a sign of credibility. But that's just me