Who is maria the hedgehog

Alright, Maria was not originally a hedgehog at all! In fact, she is Dr. Gerald Robotnik's uh... child or grandaughter. (Can't remember which one haha...) She was on the Space Coloney ARK with Shadow the Hedgehog and she died there saving Shadow.

A quick google search of the Space Coloney ARK and Maria robotnik should hopefully give you a better understanding. People have made fanart of her being a hedgehog and such but in actual fact she was a human and died. You can read all about the events that took place when she died and stuff just by googling those two things I mentioned beforehand. Hope that will clear up your confusion! :)