In order for you to have a fare chance of creating isolation (sometimes it just happens...) you need to be hooked into the set. Or else its weird. (If you dont have a good reason..)

There are diffrent ways of creating isolation and diffrent types of isolation.

Standing set: Use your body. Do a little compliance test, make her spin.
Then put yourself between her and the rest of the set in a natural way.
Lower your voice and lean back. She will lean in and *whoola* you got isolation and good bodylanguage.

Come up with somegood reasons for taking a walk threw the club.
Create a routine that gives you a natural reason for doing this.
"So you're saying you have the abillity to tell from what you see if a person is nice or and asshole? Lets find out"
Tell her friends you'll be back in 5.

If you have a really good connection with your target just ask her to
go sit down and talk a bit. If she's allready started to invest in you she shouldn't be to hard to convince.

I hope some of this can help you.
This is working really good for me, as long as its done with confidence and a good connection.
For her to be alone for a while with you should feel like the most natural thing to do. Dont make it a big deal.