During the revolutionary war a family of patriots lives on a farm/estate and there is a very sneaky British spy that no one can capture. British spy captures brother at farm, sister serves spy tea and drugs him and captures him. Spy in jail, breaks out, sneaks back to ask sister to wait for him until war is over and he will come back to marry her. He does come back after war. Light hearted book.
That’s THE SHERWOOD RING, by Elizabeth Marie Pope
Sounds like Elizabeth Marie Pope’s The Sherwood Ring. And excellent book!
That is the correct book, thank you so much!