UNCLei, I'm a UNC alumna and have been heavily involved in my sorority's recruitment efforts since I graduated.
Being a sophomore used to be a mark against women, but now, I do not believe so. There are maybe three houses that frown upon non-freshmen, but the rest of us do not. (Especially a sophomore who has shown that she can maintain an excellent GPA!)
Since you have plenty of time, go ahead and secure references for each house. It can really help you!