I think my cousin is a Lesbian?

She never talks about boys aside from her little sister who crushes and talks about boys all the time and shes kinda of a tomboy... plays basketball and has more guy friends. The other day we watched the excorsist together because her sister dared us to watch and about an hour into the movie she wrap her arms around my neck and hugged me tightly and said "so warm", it was kinda random but i just went with it. O_o she also gets jealous when her "girl" friends talk to guys... shes only 12 and i'm a 14 and i've also had this feeling that she was gay... I also caught her staring at this one girls boobies when we were at walmart. what do you guys think?? I'm I overreacting?