It wasn't allowed at my school when I was a Rush Counselor or Panhellenic Rush Chair, but we had Fall rush.
I believe our local school allows Recruitment Counselors to attend meetings but not wear letters, participate in public events or open recruitment, etc during the fall quarter (but I'm not sure.) Find out what your Panhellenic's rules are and see what you are allowed to do and not do. It's not worth a rush infraction