Did Bonhoeffer have brothers and sisters?

Yes, Bonhoeffer had three older brothers, two older sisters, one twin sister, and one younger sister: Karl-Friedrich, Walter, Klaus, Ursula, Christine, Dietrich, Sabine, and Susanne. See the major biography, Dietrich Bonhoeffer: A Life in Pictures by Renate Bethge and Christian Gremmels, for over 200 photos with brief texts providing explanation of the distinct periods in Bonhoeffer’s life.