Any Advice?

[gw5263]

I have a question about boundaries -
I have a plan to set a couple but need input. She currently only has contact through Text, Facetime, and Calls. Due to our remote location, she cannot get service for a call unless she goes up the road about a half mile. So in house she is texting whne im home, and from what i have seen in her call logs and heard from the kids, Facetiming from the house via wifi

She is afraid that i will turn her OM in for what he is doing- Should i use this as leverage for the boundaries?
If you text or facetime while in the home around the children then i will X
If you use money that you earn that should come into the home to buy him trinkets to ship to him then X? Any thoughts? I actually caught on to and defeated an attempt at manipulation yesterday. Her tactics are becoming very obvious to me now.
All along i should have caught on, I have worked in law enforcement for 21 years now and i am a trained investiogator, however all of this seemed to make me blank out, or forget some of my training until just now. I am in the process now of detaching,only answering things related to bills and the kids. I do need some advice on detachment while living in the same home with children.