As long as she is
honoring her work commitments to your family OP, then in her free time she can do whatever she wants to do. I could understand if she were to baby-sit add'l children in
your home, under your roof. For that she should ask permission.
But just to babysit in her free time, she doesn't have to ask you permission nor tell you where she is going.
I am seeing on here something that is becoming quite annoying.
Many families on here who employ a live-in nanny act like they are her parents as well.
They are complaining when she stays out all night, when she goes in the kitchen, who stays in her room, what she does on her days off, where she is, etc.
It's so unfair.