How can someone see your hard drive while your in a game room?

I was playing a game in club pogo where we use screen names not our real name.This person I was playing cards with made the remark that there was some intresting stuff on my hard drive and called me by my real name.I asked her how she knew and that I was going to report her and she just came back with I will just have to dig deeper now.How could she get my real name and see my hard drive .Someone please help. This is driving me crazy.Thanks in advance