John Tyler was also the most fecund of presidents. By his first wife, Letitia, he had had eight children; by Julia, seven, the last of whom -- Pearl Tyler -- was born in 1860 just before her father died, and who lived until 1947. A few of John and Julia's grandchildren seem to have survived into the 1980s.
Firstladies.org has this to say about Julia Tyler, who made a surprisingly durable contribution to the ceremonies surrounding the presidency in the form of advocating the use of "Hail to the Chief."
"After the sadness of Letitia Tyler’s long illness and death, and the political turmoil of the Tyler administration, Julia Gardiner’s bursting on the Washington scene was both dramatic and colorful. She had youth, beauty, wit, charm and an obvious enjoyment of that she did, which disarmed the would-be critics. Unlike the hapless Mary Lincoln, Julia Tyler’s sometimes bumbling attempts at treading the political waters caused little comment. Her nepotism, however, was another matter. Her 'royalty touches' were ill-advised, but not motivated by malice or a real sense of snobbery... [and] her attempts to add to the dignity of the office were more lasting. Especially notable was her introduction of use of 'Hail to the Chief' to signal the entrance of the President. Her later years were filled with ups and downs, but her loyalty to John Tyler and all he stood for, never faltered or wavered."