Hi, Steve! I'm Jeanne- new here as well (but I already have two, yeesh).
Frank Longbottom (frankable) is a seventh year as well, so likely they've had classes together. Plus, they're both future-Order types, so friends, perhaps?
Madam (Rolanda) Hooch (racethewind) is the Flying Coach/Quidditch Referee. If he's not on the quidditch team, she likely wouldn't know him very well. (She's a bit single-minded that way.)