I don't think she's testing you. It's probably just how she is. I wouldn't like it and it would bother me enough to feel like looking for someone that had better social skills than I do, especially if I had only been seeing her a short time. I wouldn't see it as my job to tell her how to say good bye. I'd just have to weigh it against other things and make a decision about continuing.

eta: mine holds the door open, says her version of goodbye, and sees me out, same way each week.