Given Isabella passed away in Sep 1892 and only arrived in Chicago between Mar 14, 1888 and after Mar 1886, there is a short range for the date of this portrait. To narrow the range, I checked a listing of Chicago Photographers. In 1889, S.S. Finley was listed at 151 22nd Street. In 1890, Finley & Lieberherr were at 151 22nd Street and but they were not listed in 1891. Thus the Isabella Knowles’ Chicago portrait appears to have been taken on or about the year 1890. A possible date might be Nov 30, 1890 for her 37th Birthday.
The Leonhardt family lent the original of this Studio portrait to Dave Jordan in 1991 who photographed it. The Leonhardt connection to the Jordans is Margaret Jane Jordan and Muriel Leonhardt were Knowles sisters.
If you would like to add information about this picture, please contact Dave Jordan, a 2x g-grandson of William and Isabella Knowles. The Picture Reference Numbers are: Digitized Negatives: 173-07 and 173-23.