Ok so there was this cute girl in one of my classes who I re-added on facebook just now (deleted her in january) I messaged her and said:
Hey I was in a class with you and we studied in a group together a few times, remember me?
Her: I remember, =) How are you?

How do I respond to something like this, I don't know her too well at all, and how long should I wait to respond? Thanks.