My room is small and kiddish?

you could start showing her that you are maturing and act more like an adult around her and set around hints and ask for it for your birthday or something so it wont be just a waste. you can look up things and show her how you visualize it. if you really wanna change t and nothign else is working just tell her truthfuly that you will always be her baby but you want some freedom and would like you room as whatever you want it