Complex sentence: His middle child, Emily, died in 1885, outliving both of her parents and siblings and youngest, daughter, Lucille, died unmarried and childless in 1825, months before her 18th birthday.
Split into simpler sentences: His middle child, Emily, died in 1885, outliving her parents and siblings. The youngest, Lucille, died unmarried and childless in 1825, months before her 18th birthday.