You may be interested to know that the last direct descendent of Sir Evan Nepean, also named Sir Evan Nepean, died last year (2003).
He lived for many years in a village called Teffont, Wiltshire, in southern England, had 3 daughters, an illustrious army career, and The Times and Daily Telegraph, the UK's leading "establishment" newspapers, published obituaries when he died. His eldest daughter is my mother.
All the artifacts concerning Sir Evan in the Nepean Museum in Ontario (photographs of paintings, bible, etc) were donated by his daughters Susan, Judith and Gillian.