In 1902, Twachtman died. Brown recalled in a 1955 catalogue for a Rehoboth Art League exhibition that, as she looked for a new teacher, she remembered that Ida Daugherty, a former fellow student at the Art Students League, was studying if Illustration with Howard PyIe. Brown began with Pyle in the summer of 1903 at Chadds Ford along with Dougherty and Frances Devereux Jones. That fall Ethel and Ida shared a studio in Wilmington, and the former could claim: "A new world opened up to me." Another of Brown's life-long friends, Olive Rush, came to Pyle's studio in 1904. Rush Brown were two of Pyle's favorite students, and, when he left for Italy in 1910, the two women lived in the Franklin Street studios. Throughout this period, Brown was active in magazine and book illustration. She often contributed to Youth's Companion, Harper's Monthly, Collier's, Ladies' Home Journal,  Woman's Home Companion. She also illustrated Once Upon a Time ln Delaware by Katharine Pyle, and The Transfiguration of Miss Philura, by Frances Morse Kingsley. Whether in small pen and ink vignettes or in full-page illustrations taken from a painting, people dominate her illustrative art.  Every adult and child appears rendered with personality in mind.

In late 1912 or early 1913, Brown went to Paris.  She studied at the Ecole Moderne with Charles Guerin and again shared living quarters with Ethel Poyntell Canby. She exhibited at the Salon de Beaux Arts.

The next several years after Brown's return from Europe are difficult to trace. At some point during these years she studied with Hugh Breckenridge in Gloucester, Massachusetts, and was active in many art organizations in Philadelphia. She held a fellowship at the Pennsylvania Academy of the Fine Arts and was a member of the Plastic Club, the Print Club, and the Philadelphia Art Alliance. Illustration became less and less a feature in her artistic career as ortraiture and landscape painting became more important. Her portraits included a former Delaware governor, William D. Denney, and other prominent Delaware citizens. In the 1920s, she moved to Fredrica, Delaware, and bought a cottage at Rehoboth Beach. In these two places, she spent the rest of her life, and she painted many beach and coastal scenes. She
exhibited frequently in Wilmington, Baltimore, Washington, and New York.

In 1927, she organized art exhibits in Rehoboth and was an active member in Delaware art organizations. Ethel Brown Leach continued to paint until her death in 1960.

Pyle Students