Thanks for checking on this--especially with the vague information.

Unfortunately, I don't really have much more than what I shared. Elizabeth was (per the 1850) born c1827 in Alabama which seems reasonable. All that I have on her is her mention as a grandaughter in the will of Elizabeth Bonniott of Marengo County, AL c1854. This older Elizabeth was in Alabama as early as 1829, so it's reasonable to assume that grandaughter Elizabeth was born in that state.

I do see a listing in Scott County, MS which may be them. The county makes sense as a son of Elizabeth Bonniott was living there at the time:

1860 Scott County, MS
District 3, pg 99, family 660/660

M. J. Sanders, 43 SC
Elizabeth -, 27, GA
Sarah -, 5, MS
Nancy -, 2, MS

There's this listing in nearby Newton County for 1870

1870 Newton County, MS
T5 R11, pg 14, family 20/20

Sanders, Elisabeth B., 41, AL
-, Sarah S., 15, MS

So, if this is her and she later moved down to Mobile, then it would make sense for Meredith to have served in a Mississippi regiment. As you can see, I have a lot of iffy connections with these census listings.