Age is a number that indicates the number of years your body has been in existence physically- and while more years can mean more experience (and thus, more wisdom), sometimes they don't. I've met 30-somethings who act like kids and very wise 16 year olds who seem like adults in teenage bodies.

Your daughter sounds like she is not willing to accept your boundaries- it sounds like she thinks that because you're her mother, she doesn't have to consider your feelings- and that makes her more of a kid, because she still has this very important lesson to learn. While it is very, very hard, sometimes you have to let your children make the mistakes that are necessary for them to learn.

Good luck to you.