Pieter Jacobus Marthinus was die seun van Johannes Petrus Diederik van der Westhuizen en Maria Elizabeth Maree.
Uit hulle pa se sterfkennis van 1893:
eGGSA library Gravestones in South Africa Eastern Cape : Ooskaap Eastern Cape, HANKEY, Urban area Eastern Cape, HANKEY, Main cemetery W - Surnames :: Vanne - W WESTHUIZEN Pieter Jakobus Martinus, van der 1882-1964
Names of Children of deceased, and whether majors or minors.
Johanna Jacomina (Major)
Burgert Daniel (Minor)
Susanna Helena (Minor)
Maria Elisabeth (Minor)
Pieter Jacobus Marthinus (Minor)
Magdalena Gesina (Minor)
Gesina Maria (Minor)
Johannes Petrus Diedrik (Minor)
Martha Maria Catharina (Minor)
Met hulle huwelik van 1916 was hy 'n 33 jarige jonkman van Rooi-Rivier, Uniondale en sy 'n 23 jarige jonedogter van Buffelsdrift, dist. George.
eGGSA library Gravestones in South Africa Eastern Cape : Ooskaap Eastern Cape, HANKEY, Urban area Eastern Cape, HANKEY, Main cemetery W - Surnames :: Vanne - W WESTHUIZEN Pieter Jakobus Martinus, van der 1882-1964