My then husband used to change the names of half of the engines in the Thomas the Tank Engine books to female names when he was reading them to our son 30 years ago, because he thought the fact that ALL of the characters were male was sexist.

This worked until Tom learned to read and figured out what Dad had been up to.

Now, of course, there are both male and female engines.

Soon, I'm sure there will be nonbinary engines too.