The One Where Rachel's Sister Baby-Sits

S10 E5: Rachel feels like her annoying, self-indulgent younger sister, Amy, is finally on the verge of making a major change in her attitude. In order to help Amy become a more responsible person, Rachel overrides Ross' strong protests and allows Amy to baby-sit Emma. She soon regrets that decision. Meanwhile, Phoebe unknowingly thwarts Mike's "anniversary" surprise for her. Also, Monica and Chandler become concerned when Joey tries to use big words in a recommendation letter on their behalf to a child adoption agency.