He, she, it

Important things I've learned:
--Hold Ethan's hand even when he says not to
--When Ethan runs away, it means he wants to be picked up
--When Ethan acts crazy, he is almost always hungry, tired, sick, or needs a hug
--Ethan is really good at picking out what to take to "show and tell"
--5 year olds like to bargain

For some reason, mysterious to me as a native English speaker, Ethan finds it really difficult to figure out when to use he, she, and it. He consistently mixes them all up. The other day I was trying to explain that the girl next door is a "she", not a "he", and that it is "her" brother even though he is a "he". Not sure it got through.