Hmmm... it sounds like there might be some kind of infection. There are a lot of lymph nodes behind the ears, so if she's fighting an infection it might be a lymph node working, in which case treat her like she's sick.
It could be swollen from some kind of injury or bug bite, in which case disinfect it.
It could also be a pimple.
There are so many things it could be, but either way the swelling is there for a reason, and that reason should be treated.
If you can't get a hold of an on-call Dr, just do something for her pain and take her in on Monday.
at 2:53 AM on Nov. 7, 2009