Think about how much your daughter has changed in the last 6 years. Is it likely that strabismus was present and missed at age 2. Not at all likely. It it likely that it has developed sometime after that long ago examination. Absolutely.
Sensitivity to light, closing one eye and resisting having one eye covered can all be indications of strabismus or amblyopia (they are closely related).
Strabismus is more common in some neurological syndromes but most children with strabismus (2% of all USA children) are neurologically normal.
Note strabismus runs in families (20% chance of other kids having it). Anyone that reads this post that has small children: see an ophthalmologist (Eye MD) immediately if the eyes don't look right or aligned, if there is a family history of amblyopia or strabismus see an ophthalmologist about the age of 2-2.5 years. All children should be checked by and Eye MD about age three.
Be sure you are seeing an ophthalmologist or a pediatric ophthalmologist with a MD degree.
JCH III MD Eye Physician & Surgeon