S04E17 - Best Sister (Part 1)
Synopsis
Jo goes away for her first ""college weekend"" with her latest boyfriend Jason at Yale. Just after Mrs. Garrett leaves to take Jo there, Blair's sister, Meg, arrives for a surprise visit. Meg showing up unexpected is not the only surprise she has in store, she wants to become a nun. That fact is something Blair has a hard time dealing with. Meanwhile, Jo arrives back early after the car breaks down. She later has a spiritual experience and decides she too wants to become a nun.