It could be one of two things depending on how old your friend is. one is the support of Edward the great, a lovely album released by Iron Maiden :3
another less likely, less appealing reason is that she/he is a twilight fan. a series of very awful vampire books that are the kind of stories old ladies would consider masturbatory material, featuring a character named Edward Cullen. I'm not sure what the "team" part is supposed to signify but I imagine there is some sort of rivalry going on between the lead character of twilight and the lead of another awful series of books known as the vampire diaries.
It's from the twilight saga, she's likes Edward cullen more then Jacob black. This is not a sports thing. You see, Edward an Jacob are fighting for bellas love and your friend wants bella and Edward the vampire to hook up, not Jacob the wolf and bella to hook up.