The reason Esty is told she cannot leave by the women gathering in the entrance of her building is that the "eruv" is down. She is told to leave her bag behind, so packs her essentials into her clothes before exiting again. The Eruv is a line of wire surrounding her neighbourhood, which is prevalent in Hassidic communities. If any part of the wire is broken on the Sabbath (Shabbat), it cannot be repaired until the next day, and people are prohibited from carrying or pushing anything (including children) around the neighbourhood. This is why her neighbour tells her she will be okay to leave without a bag, as she doesn't have a baby to transport.