Does this girl like me and what should i do?

ok so I've known this girl since the beginning of this semester and I've known her boyfriend since I was like 8. This girl, lets say her name is Sarah, has ALWAYS laughed at my jokes. even the nerdy ones. and she always wants me to go with her places like to get a drink or something. and even though I have a friend with me in there, she still always seems to be trying to talk to me even when having the conversation with him. she always looks me in the eyes when were talking or just sitting there. She also seems very comfortable around me as well. like she made me grab my phone out of her back pocket, you know, next to the ... and well share cokes and stuff. but when shes around her bf, she seems completely content with her relationship with him.. kissing, hugging, snuggling, stuff like that. and hes a very attractive guy.. tall, handsome, on the basketball team. and shes very attractive, and I'm rather plain I guess. but I'm going insane over this.. tell me.. is there a chance she really likes me or is that just wishful thinking? if she does like me, how could I maybe sweep her off her feet and impress her? thanks for any input you can offer?