So you thought she was an INFJ, and are slightly disappointed/worried that she tested INFP? Is this because ENTPs and INFPs don't have a rep for cliquing?
Well, first, one test doesn't mean that much (have you given her a cognitive functions test?), and it's only theory after all.
Second, you can say what you think, but you have to take into consideration her sensitive feelings when you say it. Say it in the most constructive and gentle way you can. As for being a drama queen...I never saw ENTPs that way, so maybe it's just you?
Seriously though, the extrovert need for attention and interaction can seem overwhelming at times, and it can make them seem like "too much", which might seem like drama or attention-whoring.
As for "hidden agendas", well, INFXs may have some grand, ideal vision, but if they are close enough to you, then they will usually share it with you. I suppose the only way it can get "too late" is if you never form a close enough relationship. You can prod a little too, as long as it's not pushy. NFs usually love to discuss their inner hopes & dreams.