When Mayer merged with others to form Metro-Goldwyn-Mayer in 1924, she worked as a director's assistant with that company. She edited several films starring Greta Garbo.
Among films she edited were Mutiny on the Bounty 1935 (for which she was nominated for an Academy Award), The Way We Were, and The Goodbye Girl. She also directed a few films as well, including e Slugger's Wife in 1985 at age 87.
She received an honorary Academy Award in 1977 for her work in film editing. Booth holds the record for the longest-lived person who ever won an Oscar or Academy Award.