Complex sentence: She has also reported being informed that Erwin Rommel "did" have a youngest brother named Manfred-who died in infancy; thus, Barr claims, she did not "invent" a character, but only recycled one which the universe prematurely discarded.
Split into simpler sentences: She has also reported being informed that Erwin Rommel "did" have a youngest brother named Manfred, who died in infancy. Thus, Barr claims, she did not "invent" a character, but only recycled one whom the universe had prematurely discarded.