Myrtle was the seventh child (of eight) of an Ohio businessman-farmer. Her parents were strict Methodists, but Myrtle rejected their puritanical teachings. She contracted tuberculosis at a young age. Also at a young age she developed a strong enjoyment of reading. At the age of twenty one she enrolled in the (one year) 'Literary Course for Ladies' at Oberlin College. After graduating in 1867, she taught in public schools in Clinton, Missouri, spending the next thirteen years there, except for a year in 1877-78 spent recovering from tuberculosis in Denison, Texas. In Denison, she met her future husband, Charles Fillmore, who was nine years younger than she, and they married in 1881. They lived initially in Gunnison, Colorado, Then moved to Pueblo, Colorado, where their first two sons were born, Lowell in 1882 and Rickert in 1884. The family then moved to Omaha, Nebraska and then Kansas City, Missouri, where their third son, Royal, was born in 1885.