Knapp came from a surprisingly long-lived family; eight of her siblings reached age 80 and beyond, and one sister lived to be more than 100 years old. 108 years old, in fact.
Knapp's death left Carrie C. White (18 November 1874? - 14 February 1991, 116 years 88 days?) as the new oldest living person. However, White's claim may be discounted, as there is evidence that she may have been admitted into a mental institution at age 21, rather than 35, making her only 102 at death, not 116. If White's claim is discounted, Jeanne Calment would have been Knapp's successor to the title of oldest living person, at the sprightly age of 112.
Knapp is currently the 61st oldest person on record as well as the 29th oldest American ever, both records tying with Elena Slough of New Jersey, U.S. (1889-2003).