You asked this girl and and she said maybe and shock her sholder what do you say to her now you want to send her a message saying if its no if you can still be friends and tell her why you like her?

do just that. but if you do it in person it would mean so much more, and she might be convinced to go out with you because you had the guts to say that to her face. just go up to her and say "hey umm, even if you don't want to go out with me, I still want to be good friends, and I prosmise I'll try to keep things from getting weird but if you ever want to rethink your answer, the offer is still open" and go on to tell her why you thought her worthy of being asked by you. trust me, if she looks on you with disdain after doing this, then she is not worth it all. you sound like a very mature kind of guy, I would be lucky to be asked out by you, so she is a very lucky girl, Good luck!