If you haven't already tracked down basic early records I can help you.
I am trying to find any information at all about Johanna van der Merwe who married Joseph Christopher Grant. There son was my Grandfather - James Clement Grant, who was born in 1911. I have no other information at all about her and have hit a dead end.
I have Van der Merwe's on the other side of my family and have found quite a bit so am happy to help you if you are still at that point.