I mean, I get that she's rather tiny and he's not even really human despite looking that way, but... come on.
Her hand was like a newborn's... And his single finger looks like it would be about a 3rd of the length of her whole arm, probably...
While I firmly believe all the age critiques are justified, as devil's advocate I should note that for all we know, she's a normal sized adult and he's just giant-sized.