Who is Mary Silvina Burhardt Du Bois from the book, W. E. B. Du Bois, 1868-1919: Biography of a Race?

Mary Silvina was Du Bois' mother. Du Bois blamed Mary for removing his father from their lives.

"Gnawing suspicions (possibly even a few hard facts) about the reasons for his father's disappearance led him to cling to paternal mythology - to gild Alfred's portrait - and to blame Mary Silvina for removing him from their lives. After all, it was she who had acquiesced in the Burghardt clan's putative opposition to their going to Connecticut. At bottom, she had deserted his father and was largely responsible, therefore, for their demeaning material predicament in Great Barrington. Undereducated and infirm, Mary Silvina, his 'good chum.' was now an albatross, although the more this cruel, disloyal thought insinuated itself, the more evasive, ambivalent, and wretched Willie's feelings for her must have become."