Much of her activity as a child actress in Hollywood is lost or uncredited; her first accredited film role was as 'the Girl' in a 1927 short comedy, The Bum's Rush, featuring expat Australian star Snub Pollard.

Some of her more prominent film roles were in:The Bum's Rush (1927), Saloon Bar (1940), South American George (1941)One Exciting Night (1944), Suddenly, Last Summer (1959), Victim (1961), and Philadelphia, Here I Come!

[14][16] Mavis met her future husband, Captain Donald E. Miller, at the American Eagle Club in Charing Cross Road, London, in 1941.

The couple were married in London on 16 June 1945 and planned to settle in the United States after Mavis had completed a contractual obligation to appear in a French film, Le Battalion du ciel (1946) (1946).

[17] Before they could be reunited, Donald, now working for Pan-American Airways in San Francisco, died from injuries sustained in a car accident on 4 April 1946, nine months after their marriage.