Guernica by Picasso
Picasso, Guernica
Etching by Goya
Goya, 'No one knows wherefore', etching, Disasters of War #36
Etching by Kollwitz
Kaethe Kollwitz, The Prisoners, etching
She did not herself mention specific images by Goya and Kollwitz, but I know that she was familiar with the ones here, and they seem to me to illustrate her point.