OMFG I did the EXACT same thing a couple days ago! I was at a party and went up to this guy I met earlier and said "hey Steve," He said "Hey man." "Do you remember my name

?" "Mark right?" and there was a really hot girl next to him and she said "I knew it was Mark." (Never seen her before, ever).
"No you didn't, you don't even know me." Then I paused and surveyed her quickly.
"Sarah?" a COMPLETE shot in the dark. She freaked out because that was her name. I just thought she looked a bit like a Sarah, and it is a common name. She was so bewildered, I think it creeped her out a bit because she didn't really want to talk to me much later haha. Thats crazy bro. Same story, same name.
Anyways, back on topic. I would single her out and say something like "I have an intuition about you, I'll tell you in a second." Then continue. Or "You look like the leader of your group, your friends look at you when they are thinking of a response." Or just be more interesting/project your voice better. You can do a lot of things like complement her or neg her as well.