I have the same book and knew the author. She was the daughter of Robert and Viola Winmill who were from Warrenton, VA, and are buried there. Virginia Livingston-Armstrong passed away about 12-13 years ago. She had been living in Switzerland prior to her death.
Robert Winmill was my great uncle. (His sister was my grandmother), which made Virginia my 1st cousin, once removed.
The information in the book caused me to pursue hunting for ancestors in Bishop's Stortford. When I spent an afternoon there about one year ago, there did not seem to be any traces of the Winmill family. Had I taken more time, no doubt something would have turned up.
I'm now back in the US (Virginia) and must rely on libraries and the internet to get further data on the Winmills of Bishop's Stortford. My brother recently gave me a pair of tintype photos of Samuel and Ann Winmill, who were Albert's parents. The photos were taken at a studio in Colchester.
If you get any more information, please let me know. -- Thanks.