Howard had been in movies since 1925, starting with the silent western Circus Cyclone. Other significant films she appeared in include the 1927 version of Uncle Tom’s Cabin, in which she played Aunt Chloe; the landmark all-black talkie Hearts in Dixie (1929) with Stepin Fetchit, Clarence Muse, Eugene Jackson, and A.C.H. Billbrew; the 1929 version of Show Boat, in which she replaced Tess Gardella as Queenie; the 1931 version of Penrod and Sam; George White’s Scandals (1934) and Peck’s Bad Boy (1934). Her last film was Carolina (1934), based on Paul Green’s The House of Connelly, originally prodcued by the Group Theatre. She made 22 films in all.
I am assuming a stage background prior to her film experience though I have not yet uncovered any specifics other than that she was born in Hot Springs, Arkansas. She was only 41 when she died; Mae West is said to have paid for her funeral expenses. Many or most of her screen characters were maids and other domestics. Five years after her passing, the Beulah character debuted on radio. Was Marlin Hurt inspired by Howard? Mayhap, mayhap.
To learn more about vaudeville, please see No Applause, Just Throw Money: The Book That Made Vaudeville Famous, and for more on classic comedy please read Chain of Fools: Silent Comedy and Its Legacies from Nickelodeons to Youtube.