Isolate the target this night - it was my biggest flaw. What daffy said is accurate:
To answer your question, Fredyyy, there are several ways to isolate the target once you've won over the group. Say things like:
"Okay, so -target name- and I like each other, we're going to step over here and have a chat for a minute while you guys talk."
"I'm going to borrow your friend for just a minute. You don't mind do you?"
"I hope you don't mind, but I need to talk to your friend alone for a minute. We'll be right back."
The key for this to work is you have to have made it to the point where you've been accepted by the group and she is giving IOIs. This shouldn't take long, in most situations though. In fact, the longer it takes, the less likely you are to succeed. The MOST IMPORTANT thing to remember is, it is MUCH HARDER to isolate the target in a set like this one (only 2 girls - if I isolate the target, the friend is now alone ... that's not cool and the target is far less likely to allow me to isolate her because she doesn't want to leave her friend alone). That's why it's important to have a wing. I can't even blame me not isolating her on not having a wing. I had a wingwoman with me that night. I just dropped the ball. :-/