Mrs. T.S. ALLEN, sister to WJBRYAN

I have a book about William Jennings BRYAN, by WJB and completed by his wife Mary Baird BRYAN. One of WJB's sisters, married an ALLEN and she is listed as Mrs. T.S. ALLEN. My search is "specifically" for more information on the family of this BRYAN sister and the ALLEN she married. Thanks for any help.