NTA. My son had two bi-lateral surgeries for strabisimus (squint) by the time he was five years old. His left eye still drifts at mid-distance, which he has glasses for. Here is the funny part: when I last saw my optometrist (my son sees an opthomologist) he told me that one of my eyes "flies out" at longer distances. No one in my family had ever noticed it, but it turns out that my son most likely inherited his squint from his mom's nearly imperceptible, but most definitely there, squint of her own. I am 45 with a slightly drifty eye which affects my very-long distance vision, such as looking at the stars. Doc put a focal point on one of my lenses to correct it :)
Eye surgery isn't for aesthetics, it's for function. If your opthomologist isnt concerned about function, meaning binocularity is fine except at a specific distance, then it's ok. Our sons opthomologist was worried about his brain disconnecting with his left eye altogether (monovision), so we had to work pretty diligently with the patched glasses post-op to ensure his brain welcomed his left eye back into the fold, not to mention two rounds of occupational therapy. If his eye is engaged and working then it's no biggie, like mine :) if he is bumping into things or has poor depth perception, worth booking an appointment.
This type of surgery is unpleasant. The doctor needs to operate on both eyes during this procedure, as they are re-aligning the eye muscles. You cannot rub or scratch your eyes in the day or two post-op, or you will pop the stitches and now the eye isnt attached to the muscle at all. (We made big cardboard arms for him, and we all slept in the same bed for a week after each surgery) My son also had a post-op tumour called a granuloma which effectively destroyed (and was caused by) the first surgery, pushing the left eye out further and requiring a second surgery to correct that. He still has poor depth perception, cannot write or draw very well at all, and has technology assistance written right into his IEP (he has used a laptop at school for years, he is in grade 7 now). We might do a third surgery when he is 15-16, might not, depends on the opthomologist.
So...that's the "fix" that your family is looking for...