Born in Mercersburg, Pennsylvania. She was a niece of James Buchanan and raised by Buchanan after the death or her parents. She served as official hostess for Buchanan in the White House 1857 to 1861. She was not designated as first lady and does not appear on a “First Spouse” coin.
She married Henry Elliot Johnston in 1866 and had two sons.Source credit: Pete Smith, American Numismatic Biographies