After retiring from dentistry, Griffin became Dunne's business manager, and helped negotiate her first contract. The couple became interested in real estate, later investing in the Beverly Wilshire and throughout Las Vegas (including co-founding and chairing the board of Huntridge Corporation), and partnering with Griffin's family's businesses (Griffin Equipment Company and The Griffin Wellpoint Company.) Griffin sat as a board member of numerous banks, but his offices were relocated from Century City to their home after his death, when Dunne took over as president. They had one daughter, Mary Frances (née Anna Mary Bush; 1935 – 2020), who was adopted by the couple in 1936 (finalized in 1938) from the New York Foundling Hospital, run by the Sisters of Charity of New York.
