I have found some listings of other Junior Sororities.
Alpha Kappa Psi
Eta Gamma Upsilon
Sigma Iota Chi
Phi Mu Gamma
Zeta Mu Epsilon
Theta Tau Epsilon
It is difficult to find any information on Alpha Kappa Psi since a large National Fraternity has the same name...And Phi Mu Gamma searches always end up with Phi Mu, Gamma chapter results.
The only information I have on Theta Tau Epsilon was that it was founded at Stephens' College in 1921 as well as another Junior Sorority, Kappa Delta Phi.
Beta Gamma sorority, which was said to be an AES member is so difficult to get any information on! All I know is that it is listed on Wikipedia and it says it was founded at University of Colorado. Does anyone have any information on Beta Gamma?
I also found this interesting Tumblr that might interest some of those who are responding to this thread. It is about defunct NPC and AES members!
http://defunctsorority.tumblr.com/