Who Is She?

Peter Parker is enjoying his life. Everything was going normal until one day....

"Hi, does a Peter Parker live here?"
"That's me, why?"
"Peter...I'm your sister."

After that nothing has been the same. Peter finds out the truth about his mom and realizes that his sister has some sort of power. After refusing to go to the Avengers because of someone she knows there, will she be able to control this power? How many secrets are they hiding from each other?

This is a Pietro x Reader story (Events during and after Age of Ultron, also Pietro survived)