I did a search on all the records I could find for Flora. She first shows up in St Charles in the 1880 Census - a boarder who works as a dressmaker, age 20. She states she was born in New York, her father in Canada, her mother in New York. This information is pretty consistent throughout her life - born in New York. Her father's birthplace is sometimes given as Canada but most often as France. Her mother's birthplace is usually given as Canada. In one record (the death of 3-year-old Thompson W Adams in 1903 she states Rochester, NY as her birthplace. I'd bet that she was born there and that her parents were French Canadian - that would not be uncommon for Rochester.
Flora has three daughters who marry in Michigan, where the mother's maiden name is required in the record book. In each instance it is spelled "Beauford." The common French spelling is Beaufort but Beauford is not a stretch. I tried every variable I could but no luck finding the family before 1880 - even when I added in her sister Clara.
I think the uncle who wrote the letter had too much bourbon that night