I recommend checking with your health care provider about this concern. The odor may come from earwax, but most often a foul odor indicates an infection. And babies with ear infections don't always have fever or seem sick. It's also possible at her age that she's managed to put something in her ear, like a piece of paper or small toy, that after a while could cause an odor. So I would have her examined before recommending any other remedies.