The fact that it was a mother-son writing partnership struck me as unusual, can anyone suggest any other notable examples of mother-son writing partnerships?
This is more of a trivia question so my answer will be understandably short.
Charles Todd is the pen name of the American mother-son duo Caroline and Charles Todd.
Please check the following link to know more about them: https://en.wikipedia.org/wiki/Caroline_and_Charles_Todd
Josephine Curtsinger and her son EC Curtsinger wrote a novel called 'Seldom without love' together. Here is a reference to the book I found in Google Books:
Josephine and E. C. Curtsinger, Jr. A mother-son team write a warmly entertaining first novel about a long hot summer on a farm in Prestonville, Texas in the 1930s. Anne is an engaging character who finally sacrifices her hearing aid for the church. An interesting amalgam of humor, realism and religious inspiration.
Marcel Proust collaborated with his mother Jeanne Weill Proust while translating Ruskin's works into French. This is arguably the most memorable mother-partnership in all of literature although it is a pity they didn't join forces in a more original enterprise.