After establishing a reputation for scholarship with two multi-volume books on royal ladies and noblewomen, she was invited to assist in preparing calendars (abstracts) of hitherto disorganised historical state papers.

Her father was responsible for her education, offering an extensive knowledge of history and languages, and she benefited from mixing with her parents' intellectual friends including James Everett, the minister and writer, for whom she was named.

Her subsequent work, the six-volume Lives of the Princesses of England: from the Norman Conquest (1849–1855) saw her using her skills in Latin and medieval French as well as her access to original manuscripts, letters and charters to create a biography of queens and noblewomen from the 11th century to her own time.

Palgrave, the first Deputy Keeper of the Public Record Office (PRO), had met Green, was impressed with her scholarship, especially her knowledge of languages, and recommended her to his superior John Romilly, the Master of the Rolls.

[3] Like other 19th-century women historians, Green tended to concentrate her work in fields seen as suited to "feminine" talents: research into queens and ladies, private lives, and the deciphering, translation and compilation of historical documents, for instance.

Alongside 80 men's signatures, including those of Charles Dickens, Macaulay, and Carlyle, were the women historians who depended on detailed study of freshly discovered original sources to claim authority for their work:[6] Agnes Strickland and Lucy Aikin were the other two.

Green went on working at the PRO until shortly before she died, aged 77, at home in London on 1 November 1895, having passed her research on the Hanoverian queens to her friend A. W. Ward.