Many of the SUVCW's objectives could not be attained without the support of its Auxiliary. Originally organized as the Ladies Aid Society in 1883, the Auxiliary to the SUVCW is composed of women who share the interests and goals on the Sons. They work alongside the SUVCW during special events, ceremonies and presentations.

Membership is open to those both with and without Union ancestry. Wives, daughters and mothers of SUVCW members are invited to join. A Junior membership has been established for girls 8 to 12 years old.