No she isn't.
Julie Masse is 41 years old (birthdate: June 3, 1970).
Julie Masse was born on June 3, 1970.
She is alive and she is 75 years old.
Julie-Su the Echidna is not dead. she never died. her only appearance(s) were in the Sonic comics; Knuckles the Echidna, Sonic the Hedgehog, Sonic Super Special, StH 25 and 30 years later. but...