Complex sentence: Before he met Harriet, he had met Jane Bailey who bore his child and is believed to have died during childbirth, Minnie Bailey, who stayed in the Mudgee region and had 10 children of her own.
Split into simpler sentences: Before he met Harriet, he had met Jane Bailey who bore his child and is believed to have died during childbirth. The child, Minnie Bailey, stayed in the Mudgee region and had 10 children of her own.