"I was invited to a party. May I go?"
If your first thought when your kid asks to go to a party is of the parties YOU went to as a teen, you probably want to say, "Absolutely not!" Of course, it won't be like the balloon-and-cake parties you used to plan for her, but it's worth getting more info. Ask direct questions ("Will adults be there?"), make your rules about alcohol clear, and remind her that being at a party where kids are drinking can get her in trouble even if she herself doesn't drink.