Kennelly's parents were James Daniel Kennelly, from an Irish Catholic family, and Lulu "Lula" Amanda Olsen, from a Norwegian-Swedish Mormon family; both were born in Utah. Ardyth was born in Glenada, Oregon, on April 15, 1912. The family soon moved to North Albany, Oregon, where Lula's brother George Rudolph Olsen and his family lived; but when Ardyth was about three, the Kennellys—now with another daughter, Marion, born April 12, 1915—moved back to Salt Lake City, Utah. James was killed in an accident on the job in April 1921; Lula and her daughters then moved into Salt Lake City's Constitution Building, where her mother, Anna Matilda Johnson Olsen, lived and had her chiropractic office. The Kennellys moved back to North Albany in about 1922, and in May of the following year, Lula married a widowed neighbor, Hiram Parker.