I'm going to a friend's wedding tomorrow, and I feel like an idiot, but I have no idea how much money I should give her as a gift. When it's a close friend, I typically give $100. But I don't know this girl very well, and we haven't been friends very long. She just casually invited me 2 weeks before the wedding via email because she's way under count. How much would you give? I don't have time to go shopping for a gift.