Art collector and artist Sarah Samuels Stein (1870-1953), of San Francisco, married Michael Stein, the older brother of Leo Stein and Gertrude Stein, in 1894. In 1903, she moved to Paris with her husband and their son, Allan, and lived there until 1935. She collected the works of Henri Matisse (1869-1954), promoting his career and bringing his paintings to the United States. She was also, informally, Matisse's student.
Theresa Ehrman (later Thérèse Jelenko) was born in 1884 to Jennie Rosenthal Ehrman and Hermann Ehrman, and grew up in San Francisco, where she nurtured her talent as a pianist. Her parents were friends with Michael and Sarah Samuels Stein (brother and sister-in-law of Gertrude and Leo Stein) and Thérèse taught piano to the Steins' son, Allan. When the Steins moved to Europe in 1903, Thérèse went with them, living with the family at 1 rue de Fleurus (down the street from Leo and Gertrude Stein, who lived at 27 rue de Fleurus). In Paris, Thérèse established connections with cellist Pablo Casals (1876-1973), painter Henri Matisse (1869-1954) and others who travelled in the same circles as the Steins. Thérèse accompanied Casals on the piano at times, and they remained in touch until the 1960s. She stayed in Europe until after the end of the First World War, studying the piano with Blanche Selva (1884-1942). After returning to United States, she continued to travel back to Paris throughout her life. Thérèse's three husbands were Sigmund Bauer (b. 1870), Max Schukl (b. 1869), and Victor Jalenko. She died in 1967, and had no children.
The Magnes Collection also includes the Thérèse Jelenko papers and photographs, 1899-1960 (BANC MSS 2010/603), a manuscript collection at The Bancroft Library.