Season 4, Episode 22 - "Sophia's Choice"
After taking care of Lillian for a couple of days, The Girls realize that one day they, too, will be elderly and need someone to take care of them. They make a pact. What do they promise to do for each other?
They promise to take care of each and stay together.
Dorothy tells Rose's daughter, Kirsten, about this pact. (Season 7, Episode 24 - "Home Again Rose, Part 2")
More trivia questions