Thank you so much for your reply.It fits my "guesstimates" perfectly.
I had tentatively placed my ancester in the family of a Mary Allen found in the 1850 census of Thomas Co., GA.This could be the widow of Dennis.Did Dennis die before 1850?
I have copied marriage licences found in Jefferson Co., FL, for: G. J. Allen and Mary J.(or T.) Whitaker dated July 18, 1850; married July 20, 1850 and James Allen and Martha Whitaker dated January 30, 1849; married March 19, 1849.
I had tentatively placed Mary Jane Whitaker in the family of Samuel H. and Margaret J. Whitaker identified in the Census records of Jefferson Co., FL.Their children included Margaret E., b. abt 1835 and Susan W., b. abt 1840.