Hope Lexie's feeling better. Could be a food allergy. With her ears being red, could be an ear infection. Does the ear smell? You can give you her benedryl, not sure on how many pills you should give though, I think it's 2 25mg but call your vet to make sure.
Alright, thanks guys for all the help! We beleive that it was a reaction to something because it only lasted one night.. The next morning she was feeling better and the ears didn't smell nor were they really red.. She probably got into something outside..