Hi!
I think it is a common thing at MOST schools for freshman sorority members to NOT live in the house during the first year. The main reason is because the housing situation is usually set up before classes start so that the sisters can get moved in and settled before school.
If the sorority waited to fill those slots and was depending on freshman rushees to move in, then the house might not ever get completely filled. Most freshmen already have housing set up before Rush, so it wouldn't make good sense for the sorority to count on people who aren't even in the chapter yet to be living in the sorority house.
Please tell your girlfriend that she is certainly not in the minority in this case and to not worry about the housing issue. She should definitely get a chance to live in the house at some point during her college years.
I don't know how it is with other sororities, but Delta Zeta's chapter on the UGA campus requires sisters to live in the house for at least one year. Most girls choose to do so as soon as possible, which is during their sophomore year.
Also, I'll throw in my own personal experience - I NEVER lived in the house during my time in college and it never bothered me at all. I was still able to do everything I wanted with my sisters, visited the house whenever I liked, and even spent the night on occasion. Living in the dorm as a freshman and off-campus the rest of the years never made a difference in the amount of time I spent with my sorority sisters. I even held the office of president without living in the house!
Hope this answers your question! Please tell your girlfriend GOOD LUCK WITH RUSH!