Matilda was close to her aunt and uncle. She attended Northwestern University for two years, and often visited and stayed with the Baums in Chicago. Later she spent significant periods at Ozcot in Hollywood. In her mature years years she became a important source of information for scholars and fans of Oz.
Unlike her sisters Dorothy and Alice, Matilda lived a long life, dying three months before her hundredth birthday. She preserved the papers and letters of her paternal grandmother Matilda Joslyn Gage, and made them, and her own personal knowledge, available to researchers.