You're right, it's very normal. Mine haven't done it quite that much but when ds went though his willy discovering faze we kept telling him it's for private. Make sure you tell her there isn't anything wrong with it though, just that it's meant to only be done in her bedroom. So every time you see her do it tell her she has to go somewhere private if she wants to do it. It eventually worked for ds, or he he just grew out of it! Maybe you could talk to your health nurse about different ideas too.