Complex sentence: Irene Luranah, Ira Frederick and Amanda, all of whom would go on to musical careers; and Rachael, who was born shortly after Aldridge's death and died in infancy.
Split into simpler sentences: Irene Luranah, Ira Frederick and Amanda Aldridge, all of whom would go on to musical careers. Their daughter Rachael was born shortly after Aldridge's death and died in infancy.