Thrownforaloop,
I can only imagine most if not all of us remember a time in our journey when hearing a text message on our phone made us cringe. It's good to hear you are taking some steps to protect yourself on the road to recovery.
Have you thought taking it a step further and blocking her in your phone all together? If you're worried about SS7, you may let her kindly know that any communication should come from her mother?
Thanks

And that is a good idea, but in my situation I'm feeling comfortable so far--she really doesn't like to call much. So until she starts abusing that, I'll leave it open, in case there is an emergency regarding SS7. But yes, the second she starts going abusing the contact method, I'll block it!