Well if she doesn't know how to communicate about it ... I'm just sayin'.
I do tend to think monkeystyle guessed correctly when he said A and J "bit off more than they could chew." Polyamory tends to demand good communication skills, and A has proven to be inadequate for that task -- for the moment. Hopefully this will be a learning experience for her and she'll be better at communicating in the future.
I think that as a relationship continues to mature over time, you start to test its boundaries if you feel like one or more of your own needs isn't (yet) being met therein. You want to know if some of the terms can be renegotiated. I think this is a normal part of the development of a relationship, and should not have to spell the end of it. That's just my opinion though of course. A will have her own opinion, and we'll just have to wait to find out what that is.
Love means never having to say, "Put down that meat cleaver!"