Parvati <3s all members of the DA, basically. So I think she and Ginny would be on good terms.
I'm not sure about Romilda? Maybe they don't really get on what with the whole massive crush that she used to have on Harry and that one time she used a love potion on Ron? :|
Sally-Anne probably knows her best as a Quidditch player/Harry's girlfriend.
Stebbins likely doesn't know her well.
I guess she would have known Stephen via the DA.
I daresay she and Christian have bumped into each other at some sort of event or other.
Oh, and Charlie. He loves his sister. Possibly has a tendency to see her as younger than she actually is because of the age gap and him being away at school or Romania. He can probably talk Quidditch with her for hours and isn't afraid to criticise her technique.