Ooooh, I'd be careful with that. If it were me, I'd probably interpret it with paranoia. After all, she does go through what she does and probably realizes it's not normal. I know I did. Big time. But the very last thing on earth I wanted was to delve into it. See, I recognized my behavior being like my mother's and this positively horrified me. I had vowed to never be like her. I sure didn't want anyone digging around in my head! The shame ran very deep and I couldn't deal with the thought of anyone else knowing. Worse, that I'd have to talk about it.

I definitely agree to not approach it by using words like "bipolar". In fact, I'd avoid outside perspective of how her actions affect others (can interpret as "you're impossible!" and possibly even feel like a "confirmation" that she is as horrible a person as she may well feel herself to be). Instead, it may be better to express concern over how she's feeling. Internally, not external effects on others. You of course don't know exactly how she's feeling, but something along the lines of... you've noticed that she doesn't seem to be feeling very well, love her, care very much and would like to see her be able to feel better.

Mm's idea of bringing her along to provide perspective on you is a good one. And may well bring about conversation on these things. Kudos to you btw, for being so caring. It can be very hard.