I would make an appointment with a ped opthomologist (sp?) it could be that she has an eye muscle problem that needs strengthening. Speaking from experience, it's better to be checked out sooner than later and glasses might not be the fix. A lot of optometrists just want to hand over glasses to put a bandaid on the problem.
Sorry if I haven't gotten back with anyone via PM. Still learning the iPhone app and not very "techy".