How to take care of a girl?

A little bit ago i told one of my good friends that i care about her alot, and the truth is that i do. i put her feelings before my own and i have only shown her kindness, compassion and generosity. She revealed to a mutual friend of ours that she does indeed have feeling for me and that she has for a while but what she also said is that she feels i cannot take care of her. she wants to be "taken care of" and she feels that i am not mature enough (i am a 20 year old MAN!). How can i show her that i can take care of her and that i am a mature individual?