I would buy her a skirt.
OP, like everyone else I really want to believe shes your SD, but I must admit I'm very skeptical. Lets start by just confirming whether or not you live in that house… Grab the red/black skirt and the black/white stalkings, dangle them in front of the same mirror she took the selfie while kneeling on the floor. Take it from the same angle so that we can see the skirt/stalkings, toy baskets, and dresser in the mirror. You complete that, then i'm convinced your smashing your SD or your very young wife.
Very nice slut but more proof. Have her write something on her body