WTF??? In your own home? There are children there so some type of lewdness is occurring, yes?
That's complicated. If I walked in on my stepdaughter and saw her topless, would I be charged? If she walked in on me would I be charged?
If she wasn't my biological daughter should that make a difference?
Exposing herself to the neighborhood children is not ok.
But this is complicated.
It's no worse than children walking in on parents who forgot to lock the door during some afternoon delight. Things happen. You let them know that nudity is not bad, just unfavored in a society that sells EVERYTHING with sex.