Complex sentence: Mary was daughter of Alexander Ross, a Highland Scot who had been a chief trader for the Pacific Fur Company and the North West Company, and Sally Timentwa, daughter of an Okanagan chief.
Split into simpler sentences: Mary was daughter of Alexander Ross, a Scot from the highlands who had been a chief trader for the Pacific Fur Company and then for the North West Company. Her other was Sally Timentwa, daughter of an Okanagan chief.