“Walburga was also the given name of the mother of Josef Mengele, a Nazi doctor who conducted horrific experiments on prisoners in concentration camps. She was said to have been extremely cruel and a Nazi supporter, rather like Walburga Black's views on retaining blood purity.” (Walburga Black wiki)
This being part of the entomology of Walburga Black’s name is probably telling of her treatment of those she disagreed with (see: Sirius). Also, Harry and Sirius both relating Dolores Umbridge (who repeated physically and mentally tortured Harry) is also something to note. Not to mention the constant screaming at everybody, especially Sirius, in portrait-form, and how Sirius behaves when in 12 Grimmauld Place. That was the behaviour of a man forced to live in the place he was abused.