So they are spending the night together......like a bunking party?
Well, this is a tough one for you, I am sure. Even though I don't like to see a WW immediately join in an overnight event..... I kind of think you are going to have act as if you are relaxed and trusting her. I wouldn't even require that she texts you throughout her girls night out. If she volunteers, fine, but otherwise....just show a presence of trust (even if your stomach's in knots). If she's smart, she'll know you are giving her a chance to earn a little more trust.
If there is any hanky-panky, I think it will show up. Remain calm, in fact why not go out yourself? Then the next day, you can silently evaluate your W's attitude when they come back to the house.
Don't ask her a lot of questions, b/c it could appear like interrogation.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!
