Via 1940 and 1930 census for Missouri
--Bertha was born about 1896 in MO
--With husband John, a farmer (b. in MO about 1893), had following children, also all born in MO: Rosa/Rose E. (b. about 1927); Laura J. or Laurie J. (b. about 1940); Margaret M. (b. about 1932); Georgia W. (b. about 1936) and Dave/David S. (b. about 1919); Charlie L. (b. about 1916/1917)
--In 1920, Bertha and John were living with a Mary Lee, born about 1859 in Denmark (immigration year: 1880) and a widow. She is listed as John's step-mother.
Bertha and her husband John (full name: John Claude Lee) are buried together in Chrisco Cemetary. Their graves give her as living from May 26, 1893 - Nov. 7, 1960 and him living from Feb. 2, 1891 - Sep. 7, 1958. They apparently also had a son William Thomas "Bill" born Sep. 14, 1921 (or 1923), died March 25, 1926 of an accidental gunshot wound. Source: http://shannon.mogenweb.org/cemeteries/Chrisco.htm
An Ancestry.com family tree lists Bertha's mother as David Lee (1859-1924) and Rosetta Ray (1869-1958). It lists a bunch of siblings and half-siblings for her, as it says she was married to David Lee as well as David Martin Prater.