I hated being a girl. When I was little, I wanted to be a boy (like many little girls, I believe). I was a tomboy, hated girlie things, hated things being done to my hair, hated anything related to makeup and glitter and loathed pink. I would have much preferred to be a boy.
I'm a happy heterosexual cis-woman now.
Doing "gender interventions" because a little girl (or even a teenager) is unhappy with their gender is obscene, immoral, and damaging. It may be that this child grows up and decides that they prefer to be a man. But let them wait and see and think and reflect.
Gender and sexuality are difficult things for anyone - you can't fix them in stone medically at such an immature age.