Glad to help. Cousin marriage was forbidden by some by groups (e.g., Quakers) and encouraged by others (e.g., the Ulster-Scots). It kept property in the extended family. But, we know today, had unhealthful genetic consequences. There was no civil law forbidding it that early of which I have ever heard.
New Castle (formerly often written Newcastle) County was one of the three Lower Counties owned by William Penn and his family. They owned and granted real estate but granted some self-governance to Delaware. The town of New Castle is still the kind of place that's worth a day trip for anyone in the region. So, now it is still in Delaware and includes the city of Wilmington.