what does it mean when your Girl / friend bites you and squeezes you and hits you playfully?

this girl i have known for a long time since we were 12 or 13...we meet in church. now we are both 16 and today was cold so we stayed inside during intermission, i ended up sitting next to her and out of nowhere she starts touching me...that's normal,, then she starts squeezing my side playfully,,,, that's normal, but then she bites my shoulder and my back and my arm,,??? now shes and Aquarius and im a Gemini ( that might not mean anything) i just want to know if either she has feelings for me or is she just THAT comfortable around me now?