[2] She returned to the US in 1937 and began an impressive run directing the Shakespeare play, Richard II with Maurice Evans in the title role.

They formed a partnership that lasted until 1942, with Webster directing Evans in Broadway productions of Hamlet, Twelfth Night and Henry IV, Part I.

On Broadway, Christians played Queen Gertrude in Hamlet and Lady Percy in Henry IV, Part I, staged by Webster.

When Evans joined the army, Webster continued to have success directing classical plays on Broadway, notably The Cherry Orchard (1944), starring Le Gallienne, and her greatest triumph Othello (1943), starring Paul Robeson in the title role and Jose Ferrer as Iago, which ran for 296 performances, by far the longest run of a Shakespearean production on Broadway, a record that has not been remotely approached since.

[5] In 1945, she staged the longest-running performance of Shakespeare's The Tempest to play Broadway, with Arnold Moss as Prospero, Canada Lee as Caliban, and ballerina Vera Zorina as Ariel.

[6] In 1946, Webster and Le Gallienne co-founded the American Repertory Theater with producer Cheryl Crawford, with Webster's staging of Shakespeare's Henry VIII as its premiere production, starring Le Gallienne as Katherine, Walter Hampden as Cardinal Wolsey and Victor Jory in the title role.

Her debut production of Don Carlo served as opening night of the 1950–51 season and began the tenure of Rudolf Bing as general manager.

The remainder of the money helped Webster permanently move to London after her own cancer diagnosis two years after Brundred's death.

Webster died from colon cancer at St Christopher's Hospice, 51 Lawrie Park Road, Sydenham, England in 1972, aged 67.