"It wasn't supposed to be like this." That's what Daphne Marist says at the first meeting of her new mothers' group. Daphne is wildly in love with her baby, Chloe, but she's also plagued by fear and self-doubt. So when her fellow new mother Laurel Hobbes strikes up a friendship, Daphne is thrilled. Laurel, whose daughter is also named Chloë, is everything Daphne isn't: confident, charismatic, and sophisticated. She encourages Daphne to join her gym, highlight her hair, and eat kale salads and soon the two women start to look alike, dress alike, and talk alike. But Daphne realizes only too late that being friends with Laurel will come at a price - one that she might not be willing to pay...