The Duke of Northumberland had a son, William. Lord Harcourt originally hoped that Jayne would catch the eye of the Duke’s son, but for Lord Harcourt, William proved to be feckless and a fool. Initially encouraging friendship, Lord Harcourt later forbade it outright, and in deference to her father’s wishes Jayne did not meet with William… while Lord Harcourt was at the estate.
Eventually, he planned identifying another suitable beau for his daughter. But at twenty-three, Jayne was still young - and beautiful - and in any case she had long insisted she was intent on flouting convention and never marrying.