most jobs are understanding about school & extracurricular activities.
Last summer I was looking for a job, and at the same time had 2 weeks in August (Spirit Week, and Recruitment Week) that I could not work AT ALL because we'd be so busy w/ sorority stuff.
If you plan on getting a job before recruitment begins, be honest with them and let them know before you get hired. Like my manager, I think most managers will like that you are being honest with them up front instead of just telling them what they want to hear just to get hired.
I just asked the manager in the interview how flexible the schedules could be because of school and extra curric. activities....and he didn't mind at all that there were 2 weeks that I would be unavailable.
working and being a new member (even a sister)
can be done... it just takes some time management skills
best wishes to you both in your job & greek home searches