You are Karai's sister. You are warriors of the Foot Clan and Shredder's daughters. You two fight the turtles.

During one of the battles, one of the turtles, Leonardo, to whom Splinter told that in fact you and Karai are his daughters, gave you the idea that Shredder is not your biological father...

You and your sister thought about it for a long time.

(...)

Leonardo, Donatello and Michelangelo decide to take you to the lair, thinking that you both have defected to their side. They don't know yet that Karai has activated a special device that tracks her location, and now Tiger Claw knows where the Turtles' lair is...

Raphael, seeing you with Karai, begins to scold his brothers in shock. Your sister frowns.

Karai: "We're here because we believe Splinter is our real father!"

Of course, that wasn't entirely true... Splinter comes out of the dojo and sees the two of you. He calls you into the room, then shows you a photo.

It can't be... That's Splinter standing next to your mother, when he was still human! Could it be... he's really your biological father?!