The San Antonio Light, 11 May 1916, p. 14: "Mrs. Winchester Kelso was elected president of the Battle of Flowers Association at the annual meeting of the organization Wednesday afternoon" (10 May 1916), succeeding Mrs. Atlee B. Ayres.
Image · dated 11 May 1916 · source: The San Antonio Light, 11 May 1916 (page image via NewspaperArchive).

How it is shown: Complete page as supplied; no crop, no retouch, no search highlight.
Keep in mind: Confirmed as printed. The identification of "Mrs. Winchester Kelso" with May Joyce Kelso is Likely: the papers print no first name or Sr. here.