Acute labyrinthitis

This is not so likely with her symptom pattern. She does not have tinnitus or hearing loss on one side, symptoms that you expect to see with labyrinthitis. 

The terms "acute labyrinthitis" and "acute vestibular neuronitis" tend to be regarded as synonymous. This is not the case. They should not really be interchanged. Labyrinthitis is usually an extension of a middle ear infection, viral or bacterial, and has associated tinnitus and hearing loss. 

What else would you consider