Does she like me please help?

well it my sisters boyfriends cusine, ive seen her 3 times all when family there first time in the park i went with my sister to hang out with her bf and mum and a few friends and she was there, we played like fressbe and stuff together, and then we went to sit down but the friesbes were still out so i gt up to bring then when i was about to walk back she looked at and said "awhh" and smiled. okay that was that day, the third time i saw her was at a party but again i went with my sister, i noticed her looking at me, my friend was talking and all of a sudden look at her and she was looking at me, and there was this lityle kid, me and the girl were on the same sofa sittin next to eachother, and then the kid comes up to me and look at my belt because it colourfull and had spaceinvader on it, she then touches my belt n like tugs at it and is like spaceinvaders to the little kid and touches my leg and then carries on sitting there i then gt up to get a drink. ive never really spoken to exept saying helo and stuff and kiss on cheeks but thats it, and seen her only 3 times, i added her on fb and she accepted what should i do now? were both 16 i dont know how to start with her i dont really know her so i fining hard what should i do? =\