Hi LMB I think the problem is that you based your original post on mainly ....some unknown guy wanting sex with your Mum .... as I said do not underestimate your Mums judgement in this.
Putting that aside,I do understand your concern.....does she have someone in mind, if so is it someone that you know and trust.
You are assuming that someone will take advantage of your Mum ..... but she sounds like a smart lady and I am sure that she is not incapable of making a sound judgement of someones character.
It can very lonely LMB to be alone and your Mum has had 11 long years of it, I think you should support her in this, try not to be too judgemental, meet the friends that she makes, there are lots of lovely guys out there who are lonely too, she sounds like a fine lady and you are obviously very proud, give her the credit that she deserves in making a wise choice, she is still relatively young and has many years ahead to enjoy happiness and companionship .... I really hope she finds someone really nice and worthy of such a special lady.
edited :spelling !