You might not like my advice but I want to post it anyway. I think ou should just tell her you like her....she's popular, who cares....she might like you but you don't know it. Just tell her, get over with it....find out if she likes you back, if she doesn't , at least now you know and won't have to wonder about it forever... I don't know maybe this approach is too hardcore, but I'd rather just want to know for sure instead of endless flirting that leads nowhere.