Heart and Soul (Reader x...)

The girl looked at you and your sparkling blue gown in disbelief. Here, standing in front of her, was a real, live Elsa!
“Do the magic, do the magic!” she cried, just like the young Anna in the movie.
You scrunched your hands and then let a burst of magic into the air. Again, as in the movie, the magic burst mid-air and showered all of the people in line (about six families behind the one you where currently greeting, you counted) with real snow.
You’d gotten your powers when you were a freshman in high school, to only top off the other torture in the form of acne, teasing, and an inability to fit in anywhere. You couldn’t really classify it any more than magic, the general term for your ability to create, destroy, or manipulate the world around you.
The girl squealed with glee as the photographer snapped photo after photo.
“Let’s go dear, we don’t want to tire out Queen Elsa.” The girl pouted, and you pretended to gather something before blowing sparkling crystals into her face. She gasped as the cold touched her skin, and her mother pulled out a compact mirror to show her what looked like glittering lines of frost curling and twisting above her brow bone. She squealed and clapped her hands, and the glitter would last for about a day before fading harmlessly away.
After the next few girls (and a brother, who seemed to be skeptical of your powers until you made an Olaf appear next to you), you thanked your “handlers” and went into the bathroom to change.
You pulled your hair from its long, white braid and shook it. It shifted back to its (h/l), (h/c) (h/texture) hair and you ran your hands through it. Looking down at the dress, you shifted it to a white shirt, red pants, and a black leather jacket with black knee-high boots. You pulled your cross-body bag from the magical pocket you’d made early in your self-training, and slung it across your person. If you saw any of the girls you’d just been impressing, chances were good that they wouldn’t recognize you.
“Miss (l/n)?” a man in a sharp suit asked when you stepped outside of the bathroom.
“That’s me,” you said, looking him over. “How can I help you?”
“I’m Agent Coulson with SHIELD, and lately we’ve been tracking some major magical discharge. Tracking your signals, we figured out it was you.”
“You’ve been… tracking me?” You were aware that the government could do this, but now that they acknowledged it you were stunned.
“Yes. Do you, or do you not, have magical powers?”
“I do,” you nodded. “I use them as a part of my job.”
His head tilted in a stereotypical way. “Your job?”
You nodded again. “I dress - or rather, change my appearance to look like - Elsa from Frozen. I meet little girls and, hopefully, make their day.”
He smiled. “Some of the kids I watch beg me to watch that all the time.”
“What did you want to talk about?” you asked.
“I need your help where I work,” he answered. “It’s a little bit of a secret, so I’m going to need to show you before I can tell you.”
You nodded. “Alright, let’s go.”