Stick to your guns.
You've already done what "she's been waiting, for", right? Got yourself some therapy, right? So YOU are doing, as a result of seeking the help your mother recommended, exactly what therapy has helped you understand is good for you - Setting Boundaries with her.
She will probably keep doing the same things - keep trying to get "close" (e.g., get you to give up your new boundaires), keep insisting that something is wrong with you if you don't, but don't let that get to you (as much as you can help it).
She'll probably keep at it for a long while because it has worked regularly and well in the past, so it may take a while for her to accept that you are serious (and she may never get it, at that).
Don't let that get you down, just say to yourself (and her if you think it will do any good) :
I am as close as it is healthy for me to be and will not come closer unitl/unless conditions change meaningfully and permanently.
I like to feel good and happy, so I am going to spend my time with people and situations that make me feel that way.
I am changing myself positively.
No telling what she will do or not do in response to your decision to stay distant unitl she gets help. You just have to make this yours and decide the best course for yourself, regardless.
As for the rest of the family? Maybe they'll get into the fray and stand up with you, maybe they'll cheerlead quietly but just out of sight, maybe some will get mad and accuse you of "rocking the boat" because you've had the spine to speak up about what you believe is a severe family dysfunction.
The latter especially may get you down, but try not to let it derail your efforts to become a better, stronger person.
Author NII