What to write on 18th birthday card?

My friend’s 18th birthday is coming up and I’m looking for something smart and unique to write inside the little ol’ card I’m whipping up for her. :angel: I’m about as creative as a quadriplegic walrus when it comes to thinking up original material, so I need some help here!

Oh, and not dumb immature stuff like “omglolz ur 18 go get drunk!!11!!one!!”
She’s not the kind of friend I’d write a sweet little poem to, either, so that’s out of the question.

Ideas, people! I need ideas! :hugegrin: