Hello,
As per the profile Cornelis married 3 women
1st on 30 September 1798 to Aletta Hendrina Olivier who died on 25 September 1848 dv Hendrik Olivier and Renske vd Walt
her death notice link - https://www.familysearch.org/ark:/61903/3:1:3Q9M-CSQX-MS2P-K?i=1479...
2nd on 4 April 1802 to Cornelia Gertruida van Wyk widow van Zyl
3rd on 5 October 1814 Aletta Elizabeth Ebgelbrecht
Aletta's death notice does not show any surname for husband or her children but was signed by Marthinus F G Ackerman