Mary Adeline Prentice Gilbert (November 29, 1907 - 1981) was the second child of Ezra Parmalee Prentice (1863-1955) and his wife Alta Rockefeller Prentice (1871-1962). John D. Rockefeller (1839-1937), the co-founder of Standard Oil is her maternal grandfather.
She married Benjamin Davis Gilbert on October 16, 1937 at a community named Williamsport. One source reports that Williamsport was in Massachusetts, but Pennsylvania is indeed the true location.
She is listed as a joint copyright holder (but not a joint author) with her brother John Rockefeller Prentice on a 1935 book by her father, Breeding profitable dairy cattle; a new source of national wealth (Boston and New York, Houghton Mifflin Company, 1935.) John Rockefeller Prentice is best known as a pioneer of artificial insemination in farm animals as a means of improving their genetic pool.