Thank you so much for all of your comments. I completely understand what some of you are saying, and I appreciate where you're coming from, but I would respectfully point out that you don't know my mum, nor do you know the nature of what our relationship has been like over the years, so I don't think you're necessarily best placed to know what might help her.
She is in her late 70s now, so practical help to "get back out there" is no longer particularly relevant. Believe me, I spent 20 years trying that tack and it didn't work.
I have also spent the best part of 30 years listening to how she feels and supporting her through various mental health challenges. I have never denied the validity of how she feels, nor have I tried to gloss over it. However, I do think that there is merit in helping her to get things back in perspective because her current focus on her regrets is getting in the way of her enjoying the here and now.
I agree with the person who said that she needs a purpose, and I have tried to facilitate that in different ways - suggesting voluntary activities, encouraging her to write etc. She resists all such attempts because she thinks she has nothing to offer and she believes that she has left it too late. Of course, I have tried to persuade her otherwise, but it doesn't work.
Another person said that quotes like this sound like the kind of thing you would say at a funeral. I take that point on board, but I have always felt rather sad that people wait until funerals to say what they really feel about their loved ones. I want to say those things now, while she is still alive to benefit from them.
I do get the fact that some people would not wish to receive a gift with quotes of this nature, and I respect that point of view, but we're all different. In light of the many conversations that I have had with my mum on this subject, I believe that some apt quotes might help to support a paradigm shift that would enable her to reframe some of her regrets and evaluate her life differently. Of course, it won't take away the opportunities that she has lost, but if it can help her even a little to stop feeling like a total failure, then it would be worthwhile.
Thank you to all who have provided both thoughts and quotes, and please keep the quotes coming!