S06E13: The One with Rachel's Sister (1)

Joey gets in trouble for giving attractive female customers free food at Central Perk. A sick Monica desperately tries to convince Chandler that she's not sick. After her father cuts her off, Rachel's sister Jill comes to town. Rachel encourages her to start an independent life by finding a job and an apartment, but one thing leads to another and Jill ends up asking Ross out on a date. Even though Rachel doesn't want to admit it, she clearly isn't okay with that...