On July 11, 1867, at the age of 33, Hetty married Edward Henry Green. She made him renounce all rights to her money before the wedding. The couple moved to his home in Manhattan. When her cousins tried to have her indicted for forgery based on the "Robinson v. Mandell" decision, the couple moved overseas to London, where they lived in the Langham Hotel. Their two children, Edward Howland Robinson Green (called Ned) and Harriet Sylvia Ann Howland Green Wilks (called Sylvia), were born in London: Ned on August 23, 1868, and Sylvia on January 7, 1871.