How much should I show or tell?

Be careful not to make her another Mary Sue.

Your introduction reminds me of the beginning of Empress Theresa, and you don't want to go down that path.

The "chosen teenager" is a trope and it has been done... a lot. E. g. Harry Potter, Katniss Everdeen, Percy Jackson - hell, Bella Swan almost is as well.

Lots of white kids who can save the world before band practice.

Izzy is right that this can veer into Mary Sue territory very, very quickly (Marty Stu for a male character). If you don't know what a Mary Sue character is, Google is your friend.

So, the picked on teenager who ends up being important or special or powerful, etc. is also a trope that's been done a lot. Andi in Pretty in Pink is one.

I also get that in a short story you don't have a lot of room and you want to convey contrast. But you can convey a contrast without resorting to a bang people over the head bright line distinction.

What are some of the rites of passage for Western teens, particularly American teens if you are an American and writing a story with an American MC?

* Getting a driver's license
* Getting into college (if applicable)
* Graduating
* Prom
* First kiss/seriousish relationship/possibly losing virginity

Kids in that age group are probably also starting to realize that their folks don't have all the answers and, in fact, none of the adults do. Kids can have pregnancy scares or the social problem of acne.

So, how about a contrast between her learning to drive, with all the stops and starts and things to remember, versus effortlessly flying or reading minds or whatever the super power is supposed to be? Learning to drive a stick is particularly larded up with a rather specific sequence of operations: seatbelt on, key in the ignition, one foot on the brake, one foot on the clutch, turn the key, disengage the emergency break, ease off the brake as you put the car into gear, etc. (God, I hope I got that all right; it's been over 30 years since I drove a stick).

It's a lot to remember and it has to be just so—otherwise, you can stall the car. But superhero stuff is pretty universally effortless.

You can do this with mainly telling versus showing, which should get the whole thing across without an expository data dump.

Best of luck with it!

Thanks for your suggestions guys. Maybe I should have clarified more of how I plan to convey her "differentness." Although the story is more of a conventional one with some fantasy-based elements, it's not necessarily a fantasy. Although she might have a mystical quality about her and possess some metaphysical abilities, (empath, healer, animal whisperer etc.) I wanted the "special powers" she wants to focus on to be more traditional, such as her artistic or musical talents. She pretty much makes the best of the other kids shunning her by using her alone time to "glow up", pretty much by perfecting her singing, dancing, poetry writing, etc., ultimately winning the affections of the boy her heart is set on through some type of talent competition the school is having. And she is also something of a rebel who occasionally does mischievous teenage things yes lol. I think her goal is more to be a normal kid and to want to be seen, as such regardless of whether she is "chosen" or not.

That does not sound like a short story.

After reading your and jespah's suggestions I've thought that avoiding excessive sentiment could be one way to make the story shorter. For instance I might start off by establishing that her spiritual belief systems have been stitched into her habits and thought processing all her life but that she never asked to be "special". Maybe the prologue might be of her venting to one of her animal friends that she never wanted to be some "chosen person", or that she doesn't deserve all the harassment when her unique gifts are not her fault, that being a regular working-class girl would have been enough for her. She might only celebrate and show off her differences to spite her oppressors. But I like jespah's example of learning to drive because she wants to learn to ride a motorcycle to distract herself from all the drama. The story might end with her boyfriend on the back seat with her driving instead of vice versa lol

Short stories don't tend to have prologues.