This woman is the wife of Penny's Paternal Grandfather. She is the mother of Wyatt and mother-in-law of Susan. She is the paternal grandmother of Penny, Randall and Lisa. She is the ex-paternal grandmother-in-law of Zack Johnson and the current paternal 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.
After Professor Proton asks Penny if she has any single grandmothers, Penny answers that they are both married.