At 16 she married a formal British naval lieutenant, Roger Brett, and the two relocated afterwards from the family home in New York City to their land upstate, reportedly the first permanent White settlers there.
Unlike the families that held the remaining two-thirds of the Rombout Patent, the van Cortlands and Verplanck/Kips, Catheryna not only rented but sold off parcels of her land over the years.
In partnership with Gulyne Verplank, Francis Rombout became a successful merchant-fur trader, and in 1679, mayor of New York City (following Great Britain's takeover of the former New Amsterdam).
After their marriage, the Bretts moved into the Rombout family home in New York City, which consisted of a large house and spacious grounds on lower Broadway, not far from the present site of Trinity Church.
About 1708 the Rombout Patent was partitioned, with the Van Cortlandts being allotted substantially all the land lying along both banks of Wappinger Creek; the middle portion to the heirs of Gulian Verplanck, and the lower part along the Fish Kill, some 28,000 acres, to the Brett's.
[2] In June 1718, Roger Brett drowned when his sloop encountered a fierce squall near Fishkill Landing (today's Beacon) while returning from New York City with supplies.