(-JUL 1733)
+---Richard Trethewy (ABT 1720-)
| +---Isabel Beaubery 
(-FEB 1732)
+---Philip Trethewy (ABT 1765-)
| +---Ann Jewell
+---Robert Varcoe Trethewy (ABT 1804-)
| | +---Robert Varcoe
| +---Grace Varcoe (ABT 1774-)
| +---Joan Benny
+---Richard Trethewy (ABT 1833-30 MAY 1893)
| +---Ann Guard
Sarah Anne Trethewy (26 MAR 1868-26 MAY 1878)
+---Priscilla Parsons (22 DEC 1844-14 NOV 1911)