I still have not texted her back. What would be in my best interest is to probably call her tomorrow and be kind yet very firm with my boundaries... .any guilt tripping or blaming will result in me saying "i dont want to talk about that. how was your day?" if it continues, "i have to hang up now."
Sounds like a plan.

It's so hard, but your best bet is to keep holding up those boundaries, and yes, if the conversation turns in a direction that you're not comfortable with, you can end it.
I know it's easy to scrutinize your mother's behavior and words--I've done it too. Sometimes I really have to take a step back and ask myself, "What's really driving XXX's behavior?" I've made assumptions about people's behavior too (including my mother's), but when I've stopped and really thought about things from their perspectives, sometimes I can see things differently. I do that a lot at work, as sometimes I have to deal with some difficult employee issues.
Good luck, and know that we're all here for you.