My sophmore year, identical twins went through and their mom was a XO- lucky for me- they both pledged because one is my best friend/soul sister and the other is my daughter!
My senior year another set went through and one went XO the other Delta Gamma. This was tricky because we really adored Amy but her sister just did not seem to fit in. We had no idea if they wanted to join the same sorority or not so I think we spent too much time at the parties trying to find out if they were rushing "together" or making up their own minds. It ended up happy because I realize now that the sister "did not fit in" because she really loved Delta Gamma. She seemed so moody at our parties but after I saw her with the DGees and her huge smiles all the time- I knew her heart belonged there and both girls were happy with their choice!
P.S.- for those who think sororities just pick on looks- identical twins are proof that we don't. Two girls looking exactly alike can easily pledge two different houses.