Johannes Diederik was die seun van Burgert Johannes Diederik van der Westhuizen en Francina Hendrina Barendina Kruger.
Sy naam kom voor in hulle pa se sterfkennis van 1950.
eGGSA library Gravestones in South Africa Eastern Cape : Ooskaap Eastern Cape, STEYNSBURG, Urban area Eastern Cape, STEYNSBURG, Old cemetery W - Surnames :: Vanne - W WESTHUIZEN Johannes Diederik, van der 1896-1988 & Maria Johanna 1907-1984