Thanks, friends, for your replies.
The swelling was down when I took her to the vet. Go figure. But, it was still red. My vet believes Dixie has some type of abrasion maybe from running into something. He asked me if she plays rough with my other girls and had to admit that my two others are getting older and do not play much. But Dixie plays rough by herself with toys, ever since she learned how to play (puppy mill girl originally).
He gave me something called Neo Poly Dex ointment to put on her eye lid 2 or 3 times a day, just in case.
This is a case of better safe than sorry.