Student or Learner
One guy talking with the other one said: I think this chick is up here. Susan, not that that's her real name.
I take it to mean: Of course I'm not claiming this is her real name.
What do you think?
I'd say it means he strongly doubts that Susan is her real name or he is certain that it isn't.
In Polish: nie żeby to było jej prawdziwe imię.