Quote from Rachel in The One with the Invitation
Rachel: Plus somebody's got to stay here with Phoebe. You know, she's going to be pretty big by then. She'll need someone to help her tie her shoes. Drive her to the hospital if she goes into labor. Monica: You don't have a car. And your license expired. Rachel: Yeah. See, there's so much to do, and I have so little time to do it in.