Age is obviously a factor, but the fact that you're going to be in school for a long as someone going through a recruitment as a sophomore should definitely help you out. Just be sure to mention it...you don't have to go into details, but let them know that you had a situation where you had to move home and that's why you're just now starting your life at this school. Tell them you know you have at least 3 good years there and can't wait to get involved. Obviously, there are no guarantees, but I think this will help your chances. I think it's worth it!
Good luck and like others have pointed it, recs are always a good thing. They may be able to help the chapter see more about you than just your age.
Also, if it makes you feel any better, there are girls that joined some chapters on my campus as 21 year old juniors and turned 22 shortly afterwards.