Is this the Minnie De Beers who appears in the 1900 census with son Emil and daughter Catherine? If so, please note that she is listed as being Married. I had a g-grandfather who did not appear with his wife and children after 1900. The story was that he had died while on a journey. I found out in the 1930 census that he had moved out west, "married" and had another family. Perhaps your William just absconded.