[10] From beauty pageants and glamorous photographs, she was cast in variety shows, including Earl Carroll's Vanities in 1923, 1926, and 1928, and the Ziegfeld Follies of 1924 and 1925.

Louise Brooks, who remembered Knapp as one of Ziegfeld's "prize beauties" and shared a dressing room with her, noted that "people like Walter Wanger and Gilbert Miller would meet there, ostensibly to hear my reviews of books that Herman Mankiewicz gave me to read.

"[11] In 1929 she starred on Broadway in Fioretta; the show's failure was blamed on Knapp's lack of musical talent,[12] and she was hospitalized after she was fired from the production,[13][14] and lawsuits followed.

She made public comments about withdrawing to a convent,[23] possibly in Mexico,[24] but had not done so before 1936, when she was reported living in Tudor City and making sculptures.

[25] In 1957, Walter Winchell mentioned that Knapp was working at the jewelry counter of a department store, and living with Anna May Wong.