Does this girl like me,she treats like shes a dog and im her master but zones out around her friends?

there's this girl im really good friends with and she carries my books for me(she offers,i do not ask),she always sharpens my pencil for me if need be,she always offers to keep my extra books in her locker,she does everything for me(again,she offers i never ask).but at lunch when she is around her friends she acts like she doesn't even know me and she has asked me to be her boyfriend,but won't give me her number!what do i do?she is black and im white and her friends are all black so im thinking she is embarred and we have kissed more than once.plus she has told me she is not a virgin.which i find is weird.and she has also told me that all of her friends except me,of course,and two others are s and she got into bed with one of them and that she got into bed with one of them and that is who she lost her virginity to.help!!!!!!!!!!!!!!!!