Problem with my best friend whos a girl help please?

ok my best friend whos a girl found out i liked last thursday and then friday at school she was ignoring me so then after school we went to my friends house and she was also there but she didnt say hi to me and then after she was like thanks for saying hi and then we got in a argument and i said how she ignored me at school and then the next day i went to her house with my friend and i helped her mom out with her christmas tree and then i saw her and she talked to me but only a little and i cant tell she felt awkward. she also told my friend that she doesnt wanna be in a relationship with me because i'm too much of a good friend and she doesnt wanna lose that but i know shes lieing and theres really something else bothering her and today i'm going to her house with my friend to help her parents out and also i wanna talk to her privately and ask her whats up and whys shes treating me this way and y she really cant go out with me can someone tell me what i shud do