Complex sentence: Of these three marriages, only that to Isabel resulted in a live child, but the Infanta Doña María Luísa Isabel, died on January 9,1818 at the age of four months.
Split into simpler sentences: Of these three marriages, only that to Isabel resulted in a live child. Queen Isabel's daughter, the Infanta Doña María Luísa Isabel, died on January 9,1818 at the age of four months.