Myles/Melissa
Dependant on Privilege and Reclamation
Most cisgendered, developmentally average, children can correctly state their sex at three years. Transgendered, developmentally average, children often show the first clear signs of gender variance at this age.
A three-year-old boy-shaped genius is more likely to say, "Artemis, are you aware of the phenomenon of transsexuality? I think that may apply to me," than claim to be a princess.
And even a rational, genius, older brother, who is aware most current theories on transgender believe it to be fixed at birth, is likely to panic and tell the child they're too young to know such things.