I doubt this will help much, but hopefully won't muddy the waters! From familysearch.org.
It appears from census data that Catharine/Annie had a ? sister Nancy b. abt 1840 and possibly another sister Frances b. abt 1820-1825, would married a Clark, living with Annie, then later with Emma Ward.
Maybe those additional names will help you figure out Catharine.
I found son John A and Frances (Williams) + children etc. in several later census lists but his marriage cert didn't provide any further details on the parents, nor did the marriage of his sister Lettie to Pascoe or the suspected aunt Frances to Clark. Could not find a death record for John H between 1870 and 1880 either.
US Census, 1850 Vicksburg, Warren, MS
John Fletcher M 33 TN
Catharine Fletcher F 30 TN
Frances Fletcher F 9 MS
Letha Fletcher F 7 MS
John A Fletcher M 4 MS
William M Fletcher M 2 MS
US Census 1870 Warren, Vicksburg, MS
https://familysearch.org/pal:/MM9.3.1/TH-266-11829-44953-60?cc=1438024&wc=1596958
John Fletcher M 54y TN
C Fletcher F 49y TN
W M Fletcher F 23y MS
Nancy Fletcher F 20y MS
Ida Fletcher F 12y MS
Emma Fletcher F 10y MS
Nancy Powers F 30y TN
(next household is son John )
US Census, 1880 Vicksburg, Warren, MS
self Anna Fletcher F 58 TN /GA/GA widow
dau Nancy Fletcher F 32 MS
dau Addie Fletcher F 21 MS
dau Emma Fletcher F 19 MS
other Francis Clark F 56 TN /GA/GA widow
US Census, 1900 ED 121 Beat 1 Vicksburg city Ward 2, Warren, MS
head Wm F Ward M 53 MS
wife Emma V Ward F 40 MS
dau Willie A Ward F 16 LA
son Louis E Ward M 14 MS
dau Irena Ward F 12 MS
son Fredric Ward M 4 MS
son Joseph W Ward M 0 MS
aunt Francis A Clark F 78 TN
Mississippi, Marriages
Groom: George R. Clark
Bride Frances Powers
Marriage 13 Dec 1845 Warren, MS
Groom John E. Fletcher
Bride Frances A. Williams
Marriage 26 Feb 1867 Warren, MS
Groom William H. Pascoe
Bride Lettia A. Fletcher
Marriage 30 Jul 1863 Warren, MS
