Ada is a teenage "Little Sister" who was returned to normal by Jack. She has dark brown hair tied in a ponytail and blue eyes.

Ada rescues the Rangers after they are attacked by a horde of possessed zombies and brings them to rapture. Ada explains Nefarious had come to take her but most of Nefarious's troops couldn't get past the walls of Rapture, so they left her alone. After finding enough fuel and tools to fix the malfunctioning dimensionator, Ada decides to help the Rangers.

Ada is calm, polite, good-natured, and empathetic.

Trivia:

Ada's name is a reference to ADAM.

Ada states she was the little sister that appeared on the PlayStation Allstars Battle Royale, making her the only Allstar not to be captured by Nefarious.

She's also the only Allstar who is a member of the Rangers (besides Mr. Bubbles).