Your idea was great! That would melt my heart to have kids there passing out carnations! Another idea (cheap but sweet)- chalk talk!
You write all over the sidewalk in front of the house/dorm/stairwell of the sorority- good positive things in all different colors of chalk. When the sorority wakes up the next a.m. and walks out to class- they are welcomed to things like
"Alpha Alpha rules" "We luv the Alpha's!"
Love, The Men of Sig Ep
Hope this helps! Sue