Fuck her right there or ask to leave the 'party' and go somewhere more private. Who knows maybe your friends will want to watch or join in as well!! Think what YOU want to do and HOW you want it to be with your first time with her.
Geez, you really have to ask? There isn't a surer sign. Definitely she was horny and you were the one that was making her so. Go for it!
Damn. All the times I'm so horny, yet not a single woman will come to my aid. Damn. Isn't that violating the Geneva Convention or something?