Bernadette, aka Bernie, is Sonic's mother, who was a victim of Dr. Eggman's roboticization.  While she was able to change back to normal, her husband, Jules, is permanently a robot due to his fatal injuries during the Great War.  Despite this, she and Jules still do whatever they can to protect Sonic and wait for him and his friends to come home safe...

Bernie is supposed to be a motherly figure that is usually "cool with the kids," but also worries when her son's in danger.  What I'd like for her is a typical motherly tone that's in the middle range with hints of concern in her voice.  It shouldn't be that hard to pull off, honestly, but just do the best you can for her impression.