Firstly, I want to say that I do sympathise. I know for certain that my Dad in the past has told family members about my struggling career- which has been a great source of embarassment and worry for me- so- you can imagine- that didn't help me either when it came back. Now things have picked up all year, he'll no doubt be telling everyone that he hasn't seen me in ages. So- I think you have to probably accept that in certain ways, we probably can't win.
If you think about it more though. Why are our parents talking about us at all? Probably because our well being and futures are of great concern to them. So, if we're struggling in any way, it's going to be a worry to them.
It would be nice to think that our parents were the strong stoic type who could be there for us to help us and simultaneously keep all their worries and concerns to themselves. But- they're not. They're human- like us. So, if they're worried because their child (we're still their child, no matter how old we get) is displaying alarming behaviour, (you're on a suicide forum, so your Mum is perceptive to some degree, even if she doesn't know the full extent) then, she may well be extremely worried and voice her concerns to other family members and friends. She may not be doing this with mallicious intentions. It may just be because she's also upset and needs to vent or, she's worried and she's seeing what other people make of it. Kind of understandable for a concerned parent.
Although, if it's more to express disapproval then, I sympathise. It may be a mixture of both. I suppose what I was trying to say was that the end result can feel kind of hurtful and like a betrayel but that may well not have been the intention.