Access to child's icloud

Recently we reset our 13 year old's Ipad to factory settings as she was abusing social media and had some questionable photos on there. First off, we thing (but maybe someone can confirm) that the photos would still be in her icloud. Secondly, she refuses to give us the APPLE ID and password to her icloud. We want those photos removed and trying to figure out how we get access to her icloud since she is a minor, but refuses to give us the password (going to very rebellious stage). I do not know nor do I think we had this icloud on family sharing but I can't imagine she was able to set up this Apple ID by herself since she got a MAC computer at 11 and the ipad at 12. There must be a way to access her apple ID and get into her icloud. Any help would be appreciated.