Thanks for posting your query..
Is there any optic nerve
pathology detected by the ophthalmologist?
It can be associated with other problems what she has..
If there is difference of refractive error
between the eyes, the eye which is having more power can have less vision than the sound eye ( called amblyopia
for which patch therapy was advised).
It can be done upto 7-8 yr of age to stimulate the worse eye..Squint
correction is usually meant to bring the eyes into alignment so as to improve the overall quality of vision..
Even after squint surgery you may have to make her wear glasses and continue patch therapy.. The surgery should not be delayed if it is the cause for amblyopia...
Hope I answered your query.. Take care..