I believe that Catherine is daughter of Ezra and Nancy. The 1850 Census is dated Nov 6, 1850. If Catherine is 9/12 she would have been born in the month of February 1850. Sally Ann passed away August 1849.
I also didn't see George Kerr listed in the household?
Thank you for the information on William Brewer. I will research further.
My research is done independently. Unless I communicate with others of interest.
Let me know what you think. You have been very helpful.