This is only true because you have used an inconsistent application of the labels “child” and “adult.” You consistently classify teenage male protagonists as children, while female protagonists of the same age are classified as adults. Why is Peter Pan a child while Alice is an adult?

I’m not sure why we should privilege the category of “adult” protagonists when counting noses. Is the fact that Pinocchio is a child (or a puppet, I guess) make him less male? He doesn’t want to be a real child — he wants to be a real boy. I also see little reason to exclude non-human protagonists, particularly when they are anthropomorphized. You could certainly do an interesting analysis of child vs. adult vs. non-human vs. anthropomorphized animal protagonists, but when the discussion is about the gender ratio, these other categorizations just seem like excuses to minimize the number of male protagonists.

Another way of looking at it:

Disney era: 5 female; 5 male (Pongo for 101 Dalmatians and Lady for L&T based on narrator/dominant perspective)

Post Disney: 1 female (Aristocats); 8 male; 1 ensemble

Renaissance: 4 female; 5 male; 1 ensemble

Post-Renaissance: 2 female; 8 male

In this count, the protagonists are split more or less equally in 2 eras and substantially unequal (in favor of male characters) in the other 2 eras, including the most recent.

Either way you slice it, the idea that Disney overrepresents female protagonists (in any era) holds no water.