Because Darnell and Marley were unable to have children, they adopted a daughter in 1948, Charlotte Mildred "Lola" Marley (born January 5, 1948), the actress's only child. She also planned to adopt a boy within a few years, but nothing ever came of it. In mid 1948, she became romantically involved with Joseph L. Mankiewicz, the director of "A Letter to Three Wives", and in July 1948 she filed for divorce. Mankiewicz, however, was unwilling to leave his wife for Darnell, and though the affair continued for six years, she returned to her husband. Though she called him the "great love of her life," Mankiewicz never acknowledged the affair; he only mentioned her to his biographer as a "marvelous girl with very terrifying personal problems." In 1949, Darnell went into psychotherapy for hostile emotions that she had been building since childhood. Darnell's romance with Mankiewicz influenced her personal life. When he left in late 1949 for on-location shooting of "All About Eve" (1950), Darnell fell into a depression and almost committed suicide. She continued to meet with him occasionally until production of "The Barefoot Contessa" (1954) started.