I guess it's kind of amazing that she's made it to 18 months without getting one yet - seems like everyone I know has gone through this at much a younger age.
Apparently her ears are only a bit red (although she SCREAMED when the doctor put the flashlight thingy in there), so the infection isn't severe. But she's on antibiotics.
So there you go. We have our diagnosis and our medication. I'm just praying for a good sleep for her tonight.