She is doing what makes her happy. If things go awry, she's the only one who'll be hurt. She had options and this is the one she chose.
I think it's a bad choice. The potential for disaster is great. The immediate upside is more than outweighed by the potential downside. I love her and I don't want her to pay the price which I, and only I, see printed in bold on the tag attached to her decision.
She has paved her own way, removing obstacles which were within her power to destroy and deciding to be strong in the face of those she cannot. Those most closely involved have signed off on the endeavor, for their own reasons and because she wants it very much.
No one wants her to get hurt. Everyone will try their best. She has established boundaries. She promises that they will not be breached. Everything looks good.... but then, it looked good when she tried this the last time, too.
It didn't work out that well for anyone.
She knows that I am worrying but not judging; she's an adult and capable of acting without my interference. I described my concerns, and she heard them. She knows she can count on me to be there whenever she needs me; I expect that she will need me in the not too distant future.
Smart women faced with tugs on their heartstrings .... competent grown ups who find themselves repeating patterns that have ended badly .... friends who will pick you up when you've fallen, tripping over yourself once again .... such is life.