You are doing great. It sounds to me like you did a good job handling her to-be-expected ambivalence once dinner plans were back on again. You were patient and accepting when she wanted back in on the dinner, but did not get caught up in her drama about being torn and conflicted about going. You reached your "enough point" on that score and stood by it.
Who knows, she might flip flop again, for, she might feel for the first time that she isn't being guilted into going. Then again, she might not. She might be relieved. Or, she might feel stuck, feeling unworthy of having dinner with you. WTF knows, lol. You don't need to know, you have stepped away from the dinner issue and moved on.
Oh, and don't leave an open ended invite -- well, you know where we'll be in you change your mind. That is pressure, or she will experience it as such, even if you just mean to be nice to her. She will know where you'll be, I assume, because of the kids. She can suck it up and join you or not.
