Eric Petty was nice enough to send me copies of Lucille's documents.
I have reviewed the data he sent.
My conclusions are:
Mary A, Sickles, dau of William, had a dau, Mary Catherine, b.1864, out of wedlock.I find no marriage for her prior to the one with Isaac Carson on 3 Apr 1869.Mary A's father William raises her dau as his own. (Ref: 1870 Fayette Co, IL Census)
Mary A. (Sickles) marries Isaac W, Carson on 3 Apr 1869 and has at least 2 sons, William (Oct 1869) and Thomas (1872), and maybe 3, although the third son, Isaac is not found in either the 1880 or 1900 Fayette Co IL census.
The half brother, Isaac Carson, of Mary Catherine is mentioned in Mary C's obit in 1932.
Mary A. is dead by 1879 when her first dau gets married.