India, July 30 -- For Rashida Bibi, Fridays are virtually luxurious. That day, one of the families she works for gives her a weekly break, another makes work trips to Delhi so they leave early, and a third hosts an event so they hire specialised staff. That means instead of 5.30am, she wakes up at a leisurely 8am. Her sore muscles are allowed some rest, her chai simmers longer, and her trip to the market is more of a canter and not the usual dash. The only people who grudge her Fridays are her two children, aged eight and five, who spend a tense morning under the watchful eyes of a mother anxious about their progress in school.

Last Friday, though, was anything but languid. Crouched on the floor of her shanty made of corrugated tin sheet...