S9E8: The One with Rachel's Other Sister

Rachel's sister Amy tags along for Thanksgiving at Monica's place, because her (married) boyfriend cancels their plans. While watching the parade, Joey realizes that he forgot to show up for the Days of Our Lives cast float, and he asks Phoebe's help to come up with a believable lie. The dinner goes fairly well, however, Monica constantly obsesses about anybody damaging her best china. To make matters worse, Amy comes up with a crazy scenario involving Emma, which sparks a massive argument among the gang.