I don't know if this will work for you, but here's a tool I use when my mouth starts to go into automatic overdrive. This may sound really silly, but it works...just trust me on this one.
When she does/says something and you start to take the bait and respond in your normal manner....literally say to yourself (silently of course)..."edit!" or "stop", whatever works for you. It will become a mental cue for you to rethink what you are about to say, or simply to not say anything back at all (depending upon the circumstance). Sometimes saying nothing at all in response to her allows you not to rescue/placate her....and it allows her to sit with her own feelings/words and let them echo within her.
Just try it...I know it sounds ridiculous, but I have a co-worker here who advised me to use it once on him when he'd continually repeat himself during conversations. I learned to utilize this tool with my own behavior and responses as well and well...it really helped me to change my behavior with my H. I used to find myself getting my feelings hurt as a response to something he did/didn't do...I learned to stop myself during my reaction and retrain myself to tell him in a truly honest way things I needed to tell him, rather than protecting him from his (and my) feelings.
