Hey WAW, sorry to hear that things may have taken a turn. I personally would not confront her. Yet. Be calm, be cautious, but most importantly be smart. If you are starting to lose credibility with your accusations, then you need to make sure you have enough information before you confront her. Waiting it out will serve that purpose as well as the purpose of her not realizing you are onto her. If there is something going on and you confront her this early on it, she will be extra careful to cover every track. If she thinks you're in the dark and not suspicious, you may be able to get more information than you otherwise would.
This could be really, really serious and I would do whatever it takes to get the answers you need. Just do it quietly.


"Happiness is a butterfly, which, when pursued, is always just beyond your grasp, but which, if you will sit down quietly, may alight upon you."

- Nathaniel Hawthorne