My great-grandmother died in 2003, so she doesn't qualify, but if she were still alive, she would 'only' be 103. She had two sets of great-grandparents who were born in the 1790s.
On her father's side:
Robert Feaviour born 1792 in Mendham, Suffolk.
Harriet Buckingham born 1791 in Mendham, Suffolk.
On her mother's side:
John Bunning born 1797 in Ashwicken, Norfolk.
Rebecca Harrison born 1797 in East Winch, Norfolk.
Her father and mother were both the youngest children of their families, born when their fathers were in their 50s.