The two girls were inseparable, entering society together in London in 1881. She and Laura became the central female figures of an aristocratic group of intellectuals called "The Souls" ("You are always talking about your souls," complained Lord Charles Beresford, thereby providing them with a suitable label). When Laura married Alfred Lyttelton in 1885, the first part of Margot's life ended. Laura's death in 1888 was a devastating blow from which Margot never fully recovered. As a result, Margot developed chronic insomnia which would plague her for the rest of her life.
A huge house in Cavendish Square with a staff of 14 servants was the Asquith home until they moved to 10 Downing Street. The residence of most importance in the life of the Asquiths was The Wharf in Sutton Courtenay, Oxfordshire, built in 1912. This became their weekend home away from home. It is here that gatherings of the literary, artistic and political luminaries would gather.
Asquith bore five children, only two of whom survived infancy: Elizabeth in 1897, who married Prince Antoine Bibesco of Romania in 1919 and became a writer of some note, and Anthony in 1902, who became a film director.
During World War I, Asquith's outspokenness led to a public outcry. For example, she visited a German Prisoner of war camp and she accused her shell-shocked stepson Herbert of being drunk. The negative public and media response may well have contributed to the political downfall of her husband. In 1918 she was publicly attacked in court by Noel Pemberton Billing, a right-wing MP who was convinced that the nation's war effort was being undermined by homosexuality in high society. He hinted that she was associated with the conspirators. Billing also published a poem written by Lord Alfred Douglas which referred to Margot "bound with Lesbian fillets".
After her husband's death, she was left in near penury and, though she made some money as a writer of numerous autobiographies, her financial position caused her constant concern. Her final overwhelming sadness was the separation from her daughter, Elizabeth, who had been trapped in Bucharest since 1940. Asquith schemed for her rescue but Elizabeth died of pneumonia in early 1945; she outlived her mother by only a few months.
Her writing style was not always critically accepted--the most famous review of Asquith's work came from New York wit Dorothy Parker, who wrote, "The affair between Margot Asquith and Margot Asquith will live as one of the prettiest love stories in all literature." Asquith was known for her outspokenness and acerbic wit. An apocryphal but typical story has her meeting the American film actress Jean Harlow and correcting Harlow's mispronunciation of her first name — "No, no; the 't' is silent, as in 'Harlow'."