Is it possible to become really flexible even at age 13?

I don't have enough money to sign up for dance but I practice a lot at home. I can already do my left and right split, pirouettes, high kicks, ring leap, leg holds, and straddle. I can also do some gymnastics. A girl I know who's been dancing since 7 keeps telling me that it's too late to sign up and that I'll never be as good as her. So if I do sign up, do you think it's possible that I become more flexible? I really want to be able to do my middle splits, needle, straight scorpion, and the turn where you kick out your leg. I can only turn 2 times like that. Any tips and advice? thank you for reading my question! :)