I thought of two avenues for further research. One is to look for records of your g-g-grandmother with the Kemper family before the crime took place.
The second is to search newspapers and court records to see if there was legal action taken at the time of the crime. Do you know the approximate year? If you have a birth date for you g-g-grandmother, you could estimate from that year.
On J Kemper's profile linked above, there are children listed that do not have profiles of their own. Maybe this is still a work in progress? I wish you luck with your investigation. -NGP