Sunshine Tea

If your character carries a childhood trauma of "being bullied for being different than other kids" and the thing that made them "different" was something like accelerated healing, ability to talk to animals, or using magic... You're taking a stupid cliché shortcut.

if they can heal, give them a disability or an impairment

if they can understand all languages of the world and beyond, make them mute

if they can convince anyone with their voice, make them lisp or stutter

if they can see the future, make them blind or visually impaired

Water bending? Cry a lot for anything or wetting themselves (that's a bit extreme)

Fire bending? Perpetual marks on skin resembling burns

magical strenght? Chronical illness

Magic wisdom? Neurodivergency

And so on and on (ofc the kids can't heal themselves)

If you dare, make it last till adulthood. Kid's don't get bullied for habing cool abilities, rather physical things. Make sure it's the first thing the other kids see and bully your chosen one for it. So when the stuttering girl comes running in that her song can convince someone to do anything, all the kids laugh and make fun of her stutter. "The st-st-stuttering girl thinks she can s-s-s-sing!" The kid ofc runs away, cries about it and probably never flexes their power again in front of others.

Like this:

You (technically) get a kid being bullied for their special power

They have trauma from it (probably hiding their powers as long as they can)

the grown up child realises that it was their powers that make them not live full childhood and feel robbed of it (pretty cool thing to write about imho)

You get a pretty cool magic system (magic always takes something from you, it has a cost)

If you thing more about it, you could even have adults in your story that have hidden their power for so long, they no longer can control it and are left with their disabilities making their life in their medievalesque world so hard they have to begg for a living (which could be a pretty cool social commentary)

I might need glasses