Somehow the DRP missed your question Ronel. Please next time contact one of us directly if we do not react here, as we love to help out.
Van de Merwe is a commen name in the Netherlands. Might refer to the Merwede a part (at the lower reaches, so in the Netherlands from Gelderland to the sea) of the river Maas and long ago also of the Waal. I will have a look Ronel. Give me a little time. :) I m sure you re patient as it took us to get your question about 4 months. I am really sorry!
Mabey you already found the answer. Whatever I will check the profile and the books.
Happy weekend all! :)