Thowing this out there…
Crowley was born in 1661.
Jack Ketch, the executioner, died in 1686.
Rowena was in the wind sometime after Crowley was born but before be became an adult.
It’s strongly implied via interviews that Arthur Ketch is related to Jack Ketch in some way.
It’s possible that Arthur Ketch is old as hell and knew Rowena back in the 17th century.