Adriaan Arend Kleinschmidt, b2 - Who is Adriaan Arend's mother and what sources can confirm this?

Although 1) Elisabeth De Villiers (nee Joubert) is cited here as Adriaan's biological mother and Ernst Heinrich Kleinscmidt's wife,
some cite 2) Cornelia Catharina Kleinschmidt (born Van De Caap), and others again 3) Johanna Pieternella Kleijnsmit, ZA (born Van De Caap).

It is possible that Ernst Heinrich Kleinscmidt had been married to all three at some stage, but where is the source evidence that showed he had been married to Elisabeth De Villiers (nee Joubert) , and that she is indeed his biological mother?