You say you are clueless and inexperienced and are stumbling around trying to figure this out. Well, you just ran out of time. You called in child services and now the wife knows. Shit just got real.
Talk to your PI about tactical advice. Get a divorce lawyer (even if you don't intend to get a divorce; knowledge is power) and get strategic advice from him/her. If you don't have the experience and knowledge, hire someone to give it to you. You already hired the PI. Use him. Now is the time for you to get evidence of her behavior toward the children. Without it, she will make mincemeat out of you in court.
I'm halfway through. Wow. It synthesizes everything I've learned here and spits it out in simple easy to understand, easy to implement steps. I'm newly motivated to seriously run my MAP in a really focused way. Thanks Athol.
I have three copies. One for me, one for my brother who I'm flying out to visit in a couple weeks, and one for any emergency situation that may arise. Always be prepared.