Complex sentence: She continued to write and publish even after her boys reached their majority and moved away, though her youngest son Leslie was killed in the first world war, and her eldest son Harley died in an aircraft accident while serving with the Royal Air Force in Transjordan.
Split into simpler sentences: She continued to write and publish even after her boys reached their majority and moved away. But her youngest son Leslie was killed in the first world war, and her eldest son Harley died in an aircraft accident while serving with the Royal Air Force in Transjordan.