If a 1923 death cert includes the parents' names of the deceased they probably are listed, because her obit says she died in the home of her son, assuming he knew his maternal grandparents' names.
Non-certified death certs are available for $2 from: Vital Statistics Toledo-Lucas County Health Dept. 635 N. Erie Street Toledo, OH 43624
Include a SASE, the name, date of death and a postal money order with your request. You could call the V.S. office at 419-213-4828 to see what is included on a 1923 death cert, but they won't check the actual cert for you.