Unfortunately, it looks like Florence died young. There is a death notice in the Toronto Star newspaper July 29, 1933, page 21. Her first name is never used

It says that Mrs W. C. Milson (same spelling as in the 1911 census) died at the Toronto General Hospital, following surgery. Her address was 350 Beresford Avenue. She was a "lifelong resident of Toronto", an active member of St. Paul's Anglican Church, Runnymeade. She was worthy mistress of St. Ann lodge of the L.O.B.A. , no. 416. She was also a member of the Unity Chapter, Eastern Star, no 20. She is survived by her husband William C. Milson, and 4 sons William John, Harley Alvin, Delbert Sidney and Kenneth Gordon. She has one sister, Mrs Newman. Everyone lives in Toronto...
RK