Jamie met Geneva Dunsany after Lord John Grey arranged his parole in September 1756. Jamie came to Helwater, an estate owned by Lord William Dunsany—Geneva's father and Grey's friend—to continue his sentence as Dunsany's groom. Seventeen-year-old Geneva became infatuated with Jamie.

In May 1757, when Lord Dunsany arranged a marriage between Geneva and Earl of Ellesmere who was fifty years her senior, Geneva came to Jamie and demanded that he take her virginity before her wedding. After he refused, she blackmailed him and he eventually acquiesced.

As a result of their encounter, Geneva became pregnant and gave birth to William Ransom, Jamie's son, in January 1758. She died the same day due to severe hemorrhaging. Jamie felt responsible for her death and prayed by her coffin in the night preceding her funeral.