She was born on November 2, 1926, in Iowa County, near Millersburg, Iowa to Myles and Blanche Roggentine Costello. She graduated from Millersburg High School in 1943 at the age of 16. Following her education she taught in one-room school houses in rural Iowa County. She was also an elementary school teacher in the Millersburg school system. On August 11, 1948, she was married to Robert W. Murtha at St. Bernard's Catholic Church in Millersburg. The couple farmed near Victor on the Murtha family farm until they retired in 1995 and moved to Victor. She was a member of St. Bridget's Catholic Church of Victor and the Altar and Rosary Society of the church and the American Legion Auxiliary. Onie was known as a willing volunteer for church, school and community events, notably of the annual church suppers, funeral dinners and HACAP meals. She was known for her love of flowers, and people would often drive by Onie and Bob's retirement house in Victor to see her gardens. She is survived by her husband; her children and their spouses, Diane and Rob Hayes of Des Moines, Connie and Bill Scovin of Bridgewater, Connecticut, Robert Murtha of Mankato, MN, Greg and Beth Murtha of Marshalltown and Chris and Von Miller of Runnells, Iowa; eleven grandchildren, Brian Hayes of Minneapolis, MN, Kevin Hayes (wife, Gina) of Madison, Wisconsin, Amanda MacKenzie (husband, Phil), Rachel and Michael Murtha, all of Mankato, MN, Jenny, Jacob and Jillian Miller of Runnells, Cecily and Carson Scovin of Bridgewater, Connecticut, and Emily Murtha of Marshalltown; her mother, Blanche Costello of Williamsburg; and one sister, Rita Stahl of Williamsburg. She was preceded in death by her father; one brother, Robert F. Costello; and one sister, Helen Newberry.