Hi -I'm not related, but maybe this will give you some information you lack -
1920 Caddo Co., OK, 2wd Carnegie, pg. 283, ED 42, sheet 8b,
Jared R. Cox, 70, b. IL father KY
Eliza E., wife, 57, b. KS
1910 Caddo Co., OK, city of Carnegie, pg. 221, April:
J. R. Cox, age 60, IL KY IN, stock dealer
Eliza, wife, 48, KS MO MO
Mary A. Wiley, mother, age not clear, wid., 8 children/4 living, MO IL SC
1900 Jefferson Co., KS, Union twp., pg. 370, June:
Jared R. Cox, May 1849, 51, married 18 years, IL KY IN,
Eliza E., wife, Feb. 1861, 38, 0 children, KS unk KS
Theodore, nephew, birth & age blank, IL IL IL, farm lab.
In 1880, Jared & Eliza are in Leavenworth Co., KS - living with them is brother Warren, 22 IL IN IN;in 1860 & 1870, Jared's at home with parents Lorenzo & Mary in Mason Co., IL.