Yikes. Thanks guys, some hard but wise advice. In ansewr to OutToLunch, the boundaries I've stated are that if she ever uses again I'm walking without discussion; and if things don't stay monogomous I'm also gone. But lots more to think about there anyway.
In answer to English Garden, I feel like I'm falling in love with her right now but keep yanking my heart back because of this gut feeling I get that she's not really there in the same way. If it keeps on the way it is now I expect it'll die a natural death anyway as that's not what I want, though it'll be hard to leave her or back right off.
The biggest thing I get from this is that three months really isn't long enough - but the underlying things are being addressed by her in counselling. Still, you are right about all the red flags.