y mum believes XW may not have been ready for M, and that pressure from her family made her rush into it (I mentioned before that it was a BIG deal for her to get M done before she turned 30.
That sounds plausible. The rest of us have said many times your ex-W's determination to leave and burn bridges seemed radically sudden, out-of-proportion to your one "crime", and very final. It seemed like an excuse. In many of our cases serious problems slowly festered, eroding trust and goodwill. Their impulse to leave or affair felt sudden and shocking, but we could see that festering in retrospect.
