Okay this girl keeps on staring at me and i see her every where. And when they gave me my card in homeroom she

Okay this girl keeps on staring at me and i see her every where. And when they gave me my card in homeroom she also i sat next to her at lunch with my freinds so she leaves then comes back and sits their right next to me and does nothing. Then 5 minutes later leaves and talkes with her freinds . Me i just ate my lunch nothing saying anything trying not to be a slob and now she doesn't say anything to me much