This woman is the wife of Penny's Maternal Grandfather. She is the mother of Susan and the mother-in-law of Wyatt. She is the maternal grandmother of Penny, Randall and Lisa. She is the ex-maternal grandmother-in-law of Zack Johnson and the current maternal grandmother-in-law of Leonard Hofstadter and Lisa's Husband. She is a great-grandmother to Penny's nephew. Penny's Uncle may be her possible son. Penny'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.