Apparently Brig. Gen. Goode Bryan of the 16th Reg. had a daughter named Sally Twiggs Bryan who was born in 1859. We believe the regiment was named in honor of this child. She named her son after her father per the reference below.
References to Sally Twiggs:
"Thomas married Sally Twiggs BRYAN, daughter of George Goode BRYAN, C.S.A. and Anna TWIGGS. Sally was
born in 1859 in Georgia and died in 1908 in Versailles, Kentucky at age 49.
The child from this marriage was:
+ 277 M i. Goode Bryan WALTON was born on 11 Apr 1879 in Summerville, Richmond County, GA, died on
5 Dec 1948 in Columbia, S.C. at age 69, and was buried on 6 Dec 1948 in Jones Lot, Old Silverbrook
Cemetery, Anderson, S.C.."
Source:
(Search the Southern Cousins PDF listed below for "Sally Twiggs" and the info for Sally comes up on pg 59, and she and her father are listed in the index on page 92)