Sasha seems like a pretty good character! I like the gradients on the spines and the bandages. However, I think having her be Sonic and Shadow's child seems like a pretty... overpowered trait. Maybe Dr. Robotnik tried to clone Sonic, but Shadow's DNA got there too somehow. She can still be "related" to them both, yet neither of them had any input on it since I don't think two males can have a baby biologically. Her eyes seem to be a little too far up, as well. Perhaps using references of faces would help here. If you're trying for a more semi-realistic style, I'd suggest looking at human references. If you're trying to emulate a cartoony style, I'd suggest looking at references of Sonic characters. The muzzle doesn't go that far up. Also, she seems to look a little too similar to Shadow. I'd suggest changing some of the markings on the spines a little. Maybe making the entire spines gradients would make her look less like Shadow? Overall, this is a very nice character! The colors aren't too overbearing, and with the black being a grey and the blue to balance it all out, I think Sasha makes a black and red OC work, even though her story could use a little bit of work. Good job!