Just don't. There are plenty of free girls to start a healthy relationship out there. It is poor judgement to start something with a girl doing this line of work.
If your only goal is to have fun go ahead but don't put your heart on the line, you will get hurt. If you have those thoughts it is time to switch girls. Don't visit her for a while. I've dated a few escorts, believe me, it's nothing but disapointment. I've also seen a few from being an escort driver myself and the picture they sell to the customers is very different from what really goes on behind the scenes. Just have some fun and nothing more.