Sarah S. Stilwell (Weber) was born in Concordville, Pennsylvania. Beginning in 1897 she attended the Drexel Institute where she began studing under Howard Pyle. One of Pyle's favorite students, Stilwell was invited to his summer schools at Chadds Ford in 1898 and 1899 and when Pyle moved to Wilmington in 1900, Stilwell followed. She stayed in Wilminton, living for a time at Pyle's studio, until 1910 at which time she was married and moved to Philadelphia.
Stilwell is well known for her magazine and book illustrations. Between 1903 and 1921 she frequently produced covers for Saturday Evening Post and Collier's. Some books she illustrated include Mother's Hero, The Musical Tree, Kiddie Kar Book, and The Luxury of Children and Some Other Luxuries.
Stilwell's work was influenced by Aubrey Beardsley and Art Nouveau. Her illustrations primarily depicted children, faries, fantasy characters, and women. Her figures often gestured dramatically and were placed within compositions to create sweeping lines and curves for overall decorative effects.
Sources:
Rowland Elzea and Elizabeth H. Hawkes, editors. A Small School of Art: The Students of Howard Pyle. Wilmington, DE: The Delaware Art Museum, 1980.