Listen to everyone else, run far, very far from this girl.
That being said, you have to tell your GF about your neighbor. If she does say hi when your with your GF at least you have told her, best to leave out the part where you'd like to bang her though. So when Lady Cashmoney says "who's that?" you can say "That's Jennifer, you remember my new neighbor I told you about". This definitely would have saved Mr. AOIIBrandi from a few arguments back in the day