This woman is the wife of Susan's Father. She is the mother of Susan and the mother-in-law of Wyatt. She is the maternal grandmother of Penny, Randall, as well as Penny And Randall's Sister. She is the ex-maternal grandmother-in-law of Zack Johnson and the current maternal grandmother-in-law of Leonard Hofstadter and Penny And Randall's Brother-in-law (Sister's Husband). She is a great-grandmother to Penny's nephew. Penny And Randall's Cousin may be her possible grandson.
She is mentioned after Professor Proton asks Penny if she has any single grandmothers and she answers that they are both married.