The Turn-of-the-20th Century snapshots of
the Blake & Clark Families
An 1893 platmap of Yonkers identifies an area as being owned by Mrs. Blake. It would make sense that this is where Bonnie Brook might be because Sarah B Blake is the one who had money and conceivably had received some land before her father A.S. Barnes died in 1888.
While the name "Bonnie Brook" only appears a couple times in city or social directories connected to Sarah's residence, there are a number of references to different Blakes - Sarah and Frederick and various grown children - living at 771 North Broadway. In this current map of the area of Yonkers shows that 771 North Broadway is approximately at the same place as the land identified in the 1893 map as belonging to Mrs. Blake.
Another reason this address might indicate where Bonnie Brook once was is there are references in newspaper accounts that Bonnie Brook is adjacent to Morsemere (which currently is Morsemere Place and Morsemere Road) and at the corner of Roberts Ave.
Despite these possible hints, confusion still exists as in the Yonkers City Directory, Sarah is mentioned to live at Bonnie Brook in 1906, 40 Roberts Lane in 1910, and 771 N. Broadway in 1912. One possible explanation is that "Bonnie Brook's actual address changes with street development. It's also possible there were a couple different homes built on the property owned by Sarah.
Mentions of Bonnie Brook in various newspaper stories
Published in the New York Times, September 5, 1890
Published in the New York Times, November 22, 1892.