Can you fix a iPhone that has been overcharged?

My nieces iPhone got some what wet. We took it to a Cellular Doctor, they said it was over charged (electric shock) and could fix it. So my question is, do y'all think this is it for the phone can Apple fix it? Is there something we can do to make it work? Important note she has pictures from her trip to NYC she wants to keep.

The term "over charged" does not apply.

Whoever told you that is either incompetent
(in which case they are mis-describing what is wrong)
or flat-out lying to you.

Take or send the phone to a more qualified servicer.