Sasha was once the niece of the richest man in Rapture. Her parents were killed by the Ackerman family when she was a baby. She was turned into a little sisters when she was sold by her uncle, because he got into debt with Frank Fontaine and his spliced up smugglers.  She endured a hard childhood at the Fontaine orphanage, where little sisters are created. However, before she was sold to be a little sister, she befriended a man by the name of Connie Springer. Connie and Sasha were originally assigned to each other in the ADAM gathering program. Connie escaped the program and Sasha had to be assigned to another Big Daddy.

Eventually, that Big Daddy was killed and she finds a way to reunite with Connie Springer. She then becomes sort of a daughter to him. He is her new daddy... And unlike other Little Sisters, she will protect her daddy as much as he protects her.

Sasha serves as a comedic relief character like Connie. She has big appetite and has a love for cookies. She is as upbeat and light-hearted like Connie (In a sort of Creepy Little Sister kind of way.) However, she's not useless and is not completely incapable of fighting. Even as a Little Sister, she uses her ADAM Gatherer to help out Connie gather ADAM, as well as use it as a weapon if the need comes to protect herself or Connie.