Girls only...i'm confused...is she into me or something?!?

i'm confused because last year this girl i loved rejected me ten be became closer friends and i used to walk her to her car then hug her after shool after that then the last day of school i gave her a goodbuy letter...then she says we can be "pen pals" whathever that means.....then she says we definately have to keep in touch by msn and email but we didn't keep in touch at all...then i forgot about her over the summer then when school starts we stop knowing eachother and i stop walking her to her car and hugging her after school then she keep walking by me and ignoring me and hangs out with some other guy so i do the same thing for about 3 or 4 days and then 2 days later i'm walkig outside then i hear someone calling me and i see her and her friends smilling ...so i smile back and said hi ...then 3 houres later we see eachother then we hug and say hi...girls tell me what is the meaning of this??? i tought that she wanted me to stay away from her or something like if i bring her bad memories from last year....so why is he acting nice all of a sudden? and why does she seem to really like it when she hug me for a long time???? please girls tell me what you think about it??? and what you think i should do? honestly?