Complex sentence: However, he died only three years after his father and their only daughter, Henrietta Blackford, inherited the estate as an infant; she too did not live long, and died aged 7 in 1733.
Split into simpler sentences: However, he died only three years after his father. Their only daughter and heiress, Henrietta Blackford, inherited the estate as an infant, but died aged 7 in 1733.