I just thought of something. If Splinter and Shredder were raised and grew up together like brothers, does that mean that the Shredder is the turtles uncle?!?! O_o
OMG, their related to a monster...
lol, ok. I'm just kidding. I know that's not technically true. If that was the case, then Karai would be the turtles (adopted) cousin? Well, I just thought since people say all the time that it doesn't matter if the person is adopted, it doesn't make them any less family.
Just think about it, what if the Shredder really was the turtles uncle? Karai can be either the turtles sister or cousin, but regardless does it really matter? I know Master S