Natasha:

Baby. She knew you would eventually grow up into a beautiful young woman, but you would always be her baby.

Wanda:

Red. She specifically called you this because you loved when she wore her red leather jacket. Occasionally, she would wrap you up in it and you would fall asleep almost immediately.

Bucky:

Doll face. He couldn't help it, it was part of his 1940's charm. Plus, with your long, curly eyelashes, big E/C eyes and your rosy lips, you sure looked like a doll to him.

Tony:

Kiddo. He wasn't big on pet names that he deemed too "cheesy", so Kiddo you were and Kiddo you ended up being to everyone in the Tower.

Clint:

Shortie. He didn't necessarily know how he came across this name for you and Nat tried to shake him of it, but it stuck because you were so small.

Steve:

Sweetheart. Steve, unlike Tony, was all for pet names and you seemed to especially like it when he called you sweetheart by the way you giggled softly and would tug at his fingers. So, you became his sweetheart.

Thor:

Little Rose. He thought it amusing to call you such since he found you under a rose bush. You were sometimes as prickly as a thorn as well with your short temper.

Bruce:

Cutie pie. After he managed to get all that dirt and grime off your face, you were the cutest little thing he ever saw and he was instantly mesmerized by your smile.

Pietro:

Sweets. For some reason unbeknownst to your father, you had a sweet tooth. He figured that out when you had pulled a lollipop right out of his mouth and stuck it in yours, crying every time he tried to take it from you. Lollipops were your go-to.

Loki:

Darling. Yes, it sounds like something that a husband would endearingly call his wife, but you looked like a little darling to him. In fact, if it weren't for Thor, Darling would probably be your name.