Answer by taking a quote from the following article:

Douglas was born on June 3, 1897, in Algiers, Louisiana. She was the eldest of 13 siblings. Her parents, Abe and Gertrude Douglas, nicknamed her Kid when she was young, and her family called her that throughout her childhood. It is reported that she disliked the name Lizzie.

Minnie was known as a polished professional and an independent woman who knew how to take care of herself. She presented herself to the public as being feminine and ladylike, wearing expensive dresses and jewelry, but she was aggressive when she needed to be and was not shy when it came to fighting. According to the blues musician Johnny Shines, "Any men fool with her she'd go for them right away. She didn't take no foolishness off them. Guitar, pocket knife, pistol, anything she get her hand on she'd use it". According to Homesick James, she chewed tobacco all the time, even while singing or playing the guitar, and always had a cup at hand in case she wanted to spit. Most of the music she made was autobiographical; Minnie expressed a lot of her personal life in music.  Minnie was married three times, although no marriage certificates have been found. It is believed that her first husband was Will Weldon, whom she married in the early 1920s. Her second husband was the guitarist and mandolin player Kansas Joe McCoy, whom she married in 1929. They filed for divorce in 1934. McCoy's jealousy of Minnie's professional success has been given as one reason for the breakup of their marriage. Around 1938 she met the guitarist Ernest Lawlars (Little Son Joe), who became her new musical partner, and they married shortly thereafter; Minnie's union records, covering 1939 onwards, give her name as Minnie Lawlars. He dedicated songs to her, including "Key to the World", in which he addresses her as "the woman I got now" and calls her "the key to the world." Minnie was also reported to have lived with a man known as "Squirrel" in the mid- to late 1930s.  Minnie was not religious and rarely went to church; the only time she was reported to have gone to church was to see a gospel group perform. She was baptised shortly before she died, probably to please her sister Daisy Johnson. A house in Memphis where she once lived, at 1355 Adelaide Street, still exists.

When did she start singing?