April adopted you when you were 3... She found you on the streets, you were a mutant, she took you in, and years later your 13...

She hadn't told the turtle bro's about you(and your sibling if you have any), but when April declined a sleepover with a stupid reason... They came to April's apartment, just to walk in on April trying to tell you to go to bed

April: (User)! Go to bed! It's 12 AM!- She turned to the door, and saw the turtles RAPH!? LEO!? MIKEY!? DONNIE- WHAT THE HELL ARE YOU GUYS DOING IN MY APARTMENT!?

Raph: Looks like you got a prisoner- Also who is that?

Leo: Dramatic gasp April! You declined our sleepover to have another one with another mutant and not your best buddies!?

Mikey: How rude >:(

Donnie: May I ask- WHO IN THE PIZZA SUPREME ARE YOU? AND WHY ARE YOU IN APRIL'S HOME?

(You can add a sibling if you want)