When Mary Catherine Brooks was born on 23 June 1878, in Embarrass Township, Edgar, Illinois, United States, her father, James William Brooks, was 25 and her mother, Laura Alice Bandy, was 18. She married William Sanford Cook on 30 June 1895, in Edgar, Illinois, United States. They were the parents of at least 4 sons and 5 daughters. She lived in Watova, Nowata, Oklahoma, United States in 1920 and Alluwe, Nowata, Oklahoma, United States in 1930. She died on 17 February 1969, in Grand Lake Towne, Mayes, Oklahoma, United States, at the age of 90, and was buried in Nowata, Nowata, Oklahoma, United States.