I'm just going to add my vote to the don't confront her-group. It's because you would be taking away your opportunity to interact in a friendly and supportive manner.
Best of luck!
M 16 yrs, WH62, P54 3 adult blended kids EA 11/13, BD1 6/14 PA fall 14, BD2 2/15 Piecing 2015, BD3 12/15 Separated 4/16 WH moved OW in 5/16 Divorced 6/15/17