Blow was the daughter of Henry Taylor Blow, a wealthy businessman in the lead industry, who moved his family from St. Louis to Carondelet, then an independent town, after a cholera epidemic. Blow received a very fine education, first by governesses at home and later at private schools in New Orleans and New York City. When her father was appointed ambassador to Brazil after the Civil War, Blow went with him as his secretary, later traveling to Germany where she first saw classrooms inspired by the philosophy of Friedrich Froebel, a leader in early childhood education.

Upon her return to the United States, Blow studied everything she could find on early education. Applying Froebel´s theories, she opened the United States´ first successful public kindergarten at St. Louis´ Des Peres School in 1873. Blow taught children in the morning and teachers in the afternoon. By 1883 every St. Louis public school had a kindergarten, making the city a model for the nation. Devoting her life to early education, Blow was instrumental in establishing kindergartens throughout America and traveled around the country lecturing until just before her death on March 26, 1916. She is buried in her family´s plot in Bellefontaine Cemetery.