Hello burghman: Thank you for bringing your concern here to PC.

I see this is your first post. So... welcome to Psych Central.
I can't offer you anything in the way of an authoritative answer to your question. (I am neither a mental health nor a legal professional.) In general, though, I would presume there would no way for your friend to be forced back into involuntary commitment regardless of anything she does or does not do short of expressing suicidal intent to a mental health professional she's seeing or actually making another suicide attempt which would land her back in the hospital emergency room.
Also, given that she's been released from the hospital & it sounds like is not seeing any mental health professionals, I can't imagine who would be in a position to be following up on her & taking the legal action that would be necessary to have her re-committed. Personnel from the hospital can't follow her around & swoop down on her carrying her off to the psych ward if she doesn't follow through with arranging outpatient treatment. That's simply neither practical nor realistic to say nothing of legal. So I don't see how something like that could realistically happen. I presume at this point your friend is in the clear & able to carry on with her life as she so chooses. Given that she apparently did try to take her life, it might be wise for her to seek some sort of professional mental health treatment. However whether or not to do so is her choice.
I hope you find PC to be of benefit.