For what it's worth, Gertie Millar and Lionel Monckton were married, and he wrote many of her songs, both in theater shows and for her solo performances.

Madeleine Kahn sang a few Gertie Millar songs in the Gene Wilder film "Sherlock Holmes' Younger, Smarter Brother"—the clips are well worth finding on YouTube, particularly for "Simply Crazy" and "You Don't Love as I Do." This first song was an adaptation of "I'm Simply Crazy over You" (1915) [PDF: Lib. of Congress, IN Harmony]. I believe Paul Rubens wrote the second song for the show "Houp-La."