So, I think you're right as to why the spew occurred.
And you learned some stuff.
Not to have a knee jerk reaction to new information. That she is watching and seeing your changes. A couple of things hit home - like her making the decisions all the time. Good that you heard that and acknowledged it to her, but more importantly to yourself. That she bought the MLC handbook for sure.
Ayep, they often go right back to the new normal after a spew.
So, back on your path you go. And you are among many weird people. Apparently being weird is our new normal. Just sayin....