Like ROWDYsister said, it all depends on the school you go to. Some don't require letters of recommendation, while others will ask you to provide multiple letters of recommendation for each chapter. What college are you attending?
You could also check the national websites of the chapters at your school, and they usually have lists of Alumnae chapters across the nation. You could try to contact an Alumnae chapter near you, and they'll usually help you out in getting letters of rec.
Peace out
chantillylace