The only children I have for Fanny & Calvin are Julie A., b. abt. 1841, Amelia, b. abt. 1843, John, b. abt. 1845, and Solomon, b. abt. 1848. I got this information from the 1850 census, Jackson County, Indiana. Fanny was 31 at the time and probably had more children, but I have never followed up on them. There were no Alexander children listed on the census and as Amelia was born around 1841, it fits the time after Fanny married Calvin.
I did receive an email from another Maxwell cousin who is a descendant of Calvin, and he will have that information. I am going to email him too, to exchange information. Trisha