A Christmas Under Three Flags' details personal memories of Mary Emily Donelson Wilcox, adopted granddaughter and grand niece of Rachel Donelson Jackson, wife of President Andrew Jackson, and supposedly the first baby born in the White House. The book focuses on three Christmas memories -- the first of a Christmas in the White House during the 1830s and Jackson's Presidency; the second, a Christmas in Prussia at the home of the Crown Prince, to which she was invited because her father was US minister to Berlin; the last story, a Christmas in Texas in the 1830s. Unlike the first two stories, the third one does not appear to be a personal memory, but a recounting of a story, possibly told to her as she lived in Texas while her father served as US Commissioner to the Texas Republic.