glorified slave of their younger sibling (especially if it's a brother)/parents
I don't have a big sister
A slave of her parents family and younger siblings (particularly brothers)
I don't have a big sister
A big sister is a little sister that has grown up, and is no longer capable of collecting Adam from corpses. They are in a deep sea diver suit, just like a Big Daddy. They are able to use Plasmids, and have a large needle to take Adam and transfer it into themselves.
Eleanor: If I can survive, I’ll need to become like you. I’ll need to become a big sister.
A common comeback or a sexual joke made by people
I had fun last night
I had fun last night with ur sister
The person I did last night
John: I saw u in my house last night
Carmine: yea I was doing ur sister
John: GET THE FUCK OVER HEAR