To add a little bit to what was previously posted, you will want to make doubly sure that you are 100% up to date with the finances at your original chapter and that they take you off the roster with HQ.
I've had cases where the member withdrew from school, but the chapter never takes her off the books & out of the finance computer, then bills her and then later tries to terminate her for financial delinquency 'cause no one on the finance committee remembers what happened to her.
Another item that is sometimes forgotten is facility fees. If you leave your college/university, you must pay off your full facility fee committment. Chapters have been known to forget this until the bill comes from the corporation. And then you get socked with a surprise bill (or worse, they try to find you, can't and then send you in to HQ for membership termination.. )
Ladies, I cannot stress to you enough the importance of keeping HQ up to date with your address!!
oh, and back to the topic.. if you go to the bylaws online, you will want to reference bylaws, article one, section 1, B.
that section defines an alumna member.