The September 1976 Texas Monthly article is entitled "Sisterhood is Powerful" and was written by Prudence Mackintosh, who pledged Kappa Kappa Gamma in 1962.
I also remember reading the Texas Handbook, similiar to the Official Preppy Handbook and the Southern Belle's Handbook that the proper progression for a Texas gentlewoman was
Camp Waldemar to Highland Park HS to Big Six Sorority to Junior League