 Their eldest son, John de Marquet, who died young and unmarried, was an early explorer and cattle drover who found a passage from Sydney to Cessnock where his family were granted land holdings.Blaxland Arm near the town of Laguna, New South Wales is named after him.Their youngest daughter, Louisa Australia (so named as she was the first of the Blaxland children born in Australia), lobbied the State Government and Sir Henry Parkes to keep the family estate intact and preserved to no avail.