gender pronouns in a transgender story, Help

I am having difficulty deciding which pronouns to use.
I need help. I have a story of a boy thats grade school age, but he’s girlish to a extreme. He even has a girls shape and nature but refuses to admit it to himself. He has his reasons and it will be clear when I write and post it. But the problem is, he and his mother refer to him as a boy.
He has an insulting and mean teacher that sees his feminine nature and refuses to call him anything but a girl. My question is, Is it ok to use two gender pronouns in the same story. In one chapter, when I am narrating it from his mother or his POV it is OK to refer to him as 'Him."

In the very next chapter if I’m narrating it from the teachers POV to refer to the boy student as a Girl and HER