Esther Sietmann Warner Dendel, author and artist, was born February 2, 1910, on a farm near Laurel, Iowa, to Lewis Sietmann and Grace Stanton Sietmann. She was an avid member of the 4-H club for six years, joining at the age of eleven; she became state 4-H president at the age of seventeen. She won numerous awards on local and national levels, which together gave her the money to attend her first year of college. Sietmann graduated from high school as valedictorian in 1927 and in the fall entered Iowa State College (now Iowa State University) in Ames, Iowa.

After two years at Iowa State College, Sietmann left to take a job as a Home Demonstration Agent with the Extension Department at the West Virginia Agricultural College. In 1936, she returned to Iowa State College, graduating from the Home Economics Department in 1938. Following graduation she received a Lydia Roberts Fellowship and entered Columbia University in New York City. After one year at Columbia she obtained her master's degree in art, with an emphasis in sculpture.

Sietmann was married on December 9, 1939 to botanist Robert Warner, whom she had met at Iowa State College. In 1941, he was appointed Research Director for the Firestone Rubber Company Plantation in Liberia, Africa. While in Liberia, Esther Warner met Jo Dendel, who made prints to illustrate her first book about Africa, New Song in a Strange Land. She returned to the United States in December of 1943 and taught in the Art Department of the University of Minnesota at St. Paul.

She was divorced from Robert Warner and in 1945 moved to Costa Mesa, California, where she and Jo Dendel formed a business partnership called Denwar Ceramics. She was married to Jo Dendel in 1950. Denwar Studios became a place of education, where Esther and Jo Dendel hold a weekly informal workshop to teach their craft. The workshop began in the 1960s and was still active in 1997.