Il est marié avec Ethel Ada Jenner.
Ils se sont mariés le 4 juin 1934 à Mtunzini, Zululand, South Africa.Source 1
The couple was married in the Magistrates Office, Mtunzini
Jan Hendrik was a devorcee when he married Ethel.
"South Africa, Natal Province, Civil Marriages, 1845-1955," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:KDZM-7RD : 19 February 2021), Jan Hendrik Coetzer and Ethel Ada Jenner, 04 Jun 1934; citing Mtunzini, Zululand, Natal, South Africa; 00077; National Archives and Records Service of South Africa, Pretoria; 1,938,479.