In 1854 Romilly invited Green to become an external calendars editor. In her first few years doing this work she gave birth to two of her three daughters, one of whom, Evelyn Everett-Green, became a novelist. Mary Anne Everett Green's son had been born in 1847 but died in 1876. Her husband became disabled and it was important for her to earn an income. While supplementing her work at the PRO with journalism, she pursued some private research but had no time to complete a planned book on the Hanoverian queens.