..... and a question, 'how the fuck can that happen'
I assume you're using the same Apple ID on both devices. Whatever apps you buy, notes you make, music you download, and topically, photos you take, all get synced to ALL of your devices with the same Apple ID using Apple sync unless you specifically turn it off. It's on by default! This includes emails too, both received AND sent!
To turn it off, go to Settings, iCloud, and choose there which ones you don't want to sync.
Better still, set her up with her own Apple ID and remove all traces of your ID on her iPad.