inb4
>girls start puberty earlier
Yeah but the normal age is way later than 10. Maybe 12 for girls and 13 for boys. In the West in recent years girls probably are hitting it earlier due to eating huge amounts of hormone laden meat and dairy, but the Ashnime is set in pseduo-Japan in the 1990s, you can't use zoomer Murrcan girls' early onset puberty to explain Misty's height. Misty and Ash, at 10 years old, are likely both pre-pubescent.

Also, if it were early puberty in her case, she'd also show the other signs of puberty, like her butt getting big and getting curvy in general. But no, she stays thin as a plank, she's simply way taller than Ash.

inb4
>she just ate more protein, even separately from puberty that leads to taller children
Makes no sense, Misty is the youngest of 4, usually in that sibling dynamic the 3 older ones enjoy the spoils of everything, and the runt of the litter only feeds on the scraps. Ash on the other hand is an only child and with dad away, his mum spoils him with plenty of rich nutritious food. If anyone is taking in more, higher quality protein, it's Ash not Misty.