No, Little Hawk,
Rolling Thunder was circa 1975-76. Janis Ian recorded a version of "Society's Child" (under the title "Baby I've Been Thinking") for as Blind Girl Grunt in 1966. That recording is available on Smithsononian Folkways's boxed set, "The Best of Broadside 1962-1988."
It seems to me that the bootlegger probably thought he was being clever. At the three Rolling Thunder shows I attended, Joan Baez was known as Joan Baez.
Jerry