The family moved to Los Angeles, California when she was a child, and Parker graduated from Immaculate Heart High School in 1931.
Parker was selected from among a group of extras to attend the Fox Film studio training school for younger players.
Parker starred with Tom Tyler and Carmelita Geraghty in a 1932–1933 movie serial produced by Universal Pictures entitled Jungle Mystery.
That same year, she was John Wayne's leading lady in one of the first singing cowboy movies, Riders of Destiny, and also appeared in Rainbow Ranch.
After playing the sister of Greta Garbo in 1934's The Painted Veil, Parker signed a seven-year contract with Metro-Goldwyn-Mayer.
Mickey Rooney played Andy Hardy in the series, supported by Lewis Stone, Fay Holden and Parker portraying his family members, with Ann Rutherford as his sweetheart.