The Vicksburg Evening Citizen of March 18, 1861 contains
the following;

BOVINA GUARDS----We saw in Mr. H. C. Clark's News Depot, on Saturday, a beautiful Flag which he told us was made in
this city by Mrs. Cooke, for the above named company.
It is one of the new designs of the Mississippi Flag, and the work is beautifully executed, the magnolia tree being
hard to beat.

The "Warren Volunteers" would seem to be a likely suspect.
The same newspaper had a notice for the "Warren Guards" to
attend a meeting.

Ken