If she REALLY wanted to talk... she could have use a few more words in her text... "I REALLY need to talk about _______." She also could have left a voice mail.
I agree. You have learned hard lessons about her manipulation tactics.
Don't rescue her from what she's feeling right now. She needs to experience this reality. This is what it feels like to break up a family. IMO, she should not get to reach out to you to comfort her......when she was the one who brought this all about. That point is what she has to face. She must deal with losing the man she didn't think she wanted for her H.
I know it must be terribly hard for you not to contact her. But if you did, I think it would be extremely difficult to get her to stop bothering you all through each day (just as she's done all the time). You wanted some peace, and I personally think ignoring her texts is the only way to get her to stop sending them and keeping you upset.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!