Website permissions

I have an ipad I gave to my child and I have it set to only allow approved websites from a list. So as a test I tried to go to Youtube.com. Correctly the IPad says "this site is not allowed" but then all my kid has to do is click "allow" and it lets her go to Youtube and adds it to the list. It doesn't ask for a code or approval from a parent. I do not want it to do this. For now we just have not allowed safari at all as the only solution, but I feel like it honestly shouldn't allow me to access settings without a parent code/push to my phone in general or to make changes at all without our parent code. How can I block my child from accessing settings /privacy/modifying anything at all without permission? I need to be able to control this as my child can read. She is a good kid, but I mean, she is also no dummy and can read and try to change things on her own. She is only in 2nd grade and I don't want it to be so easy for her to undo my restrictions or we might just not be keeping the iPad. Help please.