I'm also interested in knowing more about the marriage of Robert Phares Kirby and Tamson Cary Gandy. I am descended from Tamson's sister Rhoda and recently stumbled upon some of the accounts that you mention in your post.
Tamson married Alexander Gandy is Union County, Ohio, in 1853. The information I had previously received was that she died in 1855 in Pike's Peak, Colorado. This information has always puzzled me.
Since whatever information can be found about this relationship may be sensitive, we may want to consider discussing via private email.