Of Vincent's three sisters, he was closest, by far, to Wil. During the last several years of his life, Vincent corresponded with Wil, though not as frequently or as voluminously as with Theo. Still, a number of Vincent's letters to Wil survive and provide interesting insights into his life.
Unfortunately, Wil also shared with Vincent some similar mental problems. A few years after the death of Vincent and Theo, Wil was institutionalized. For the last few decades of her life, Wil had completely withdrawn from the world and didn't utter a word. She died in the asylum at the age of 79.