The Kentucky Death Records show a Gladys U. Puryear who died 1/11/1969. Is this Earl's wife?
Was your mother living in Owensboro in 1990?
It seems that Elizabeth Johnson's mother was Maria T. Chapman, so the Chapman Cemetery may be private. Elizabeth had an older brother named Robert Elza which may be where your grandfather got his middle name.
I show Francis Walker Johnson (born 4/3/1792 in Virginia) married Maria T. Chapman (born 8/18/1798 in Virginia) on 3/22/1817 in Green County, Kentucky. F. W. Johnson (father of the bride) gave consent when Elizabeth married James Puryear on 10/6/1853 in Larue County, Kentucky.
I am not sure who are the parents of James Puryear. I and at least one other researcher show his parents to be Abraham H. Puryear (about 1808 in Green County, Kentucky to before 1900 in Taylor County, Kentucky)and Sarah Shively (daughter of Jacob Shively born about 1809 in Kentucky and died before 1860 in Larue County, Kentucky). James Puyear is living next door to Abraham H. Puyear and his known son John in the 1860 census for Larue County.
The parents of Abraham H. Puryear are Samuel Puryear (1781-7/1860) and Lavinia Harding (9/19/1785 - after 1860) who married 1/19/1806 in Green County, Kentucky.
The parents of Samuel Puryear are Jesse Puryear (4/28/1754 - 10/8/1833 in Green County) and Elizabeth Rice (12/10/1758 - before 1824 in Green County) who married in Henrico County, Virginia.
The parents of Jesse Puryear are Thomas Puryear and Margaret Bowles who married 1749 in Henrico County, Virginia.
The parents of Thomas Puryear are Samuel Puryear (about 1694 - 1748 in Warwick County, Virginia) and Elizabeth (about 1698 - 1755 in Warwick County, Virginia). These are the oldest white Puryears in America to whom descendents can be traced.