Definitely do not tell her you found anything or confront her. Everytime I did that - texts, phone calls, catching them together - it backfired on me. It never once had the effect I had hoped. It is never attractive when someone loses control of their emotions.
Keep acting as if your world is fine with her or without her.
Me:38 W:39 No Children BD: 5/13 EA/PA Confirmed: 7/13 W Moved out 12/13