Season 3: Episode 50: Maybe, Baby
Jill's sister Carol is having a baby girl. When they talk about the baby's name and Jill is going through the boys' baby toys, she wishes she could have a baby girl. Tim tells Randy and Brad that Jill always wanted a girl so they tell Mark that Jill wished he had been a girl. This upsets Mark and when Jill wants to bake a cake with him, he doesn't want to. When she finds out the truth, she tells Mark that what Randy and Brad told him isn't true. Tim is also upset because he doesn't want another child. But he feels alright again when Jill tells him that they don't have the time for another child.