[DubaiSis]

Check with your local alumnae chapter for all of these details, but as a member in good standing (presuming you are) you are eligible to be a member of an alumnae association and could volunteer with your local collegiate chapter. There is no such thing as alumni initiation as far as I've ever heard. Some sororities have a "crossing over" ceremony of sorts, celebrating your transition into alumnae status in conjunction with graduation, but I can't imagine it is required to actually function as an alumna.

While the traditional lifespan of a sorority member is 3-4 years as a collegian, graduation, join an alumnae group either right after graduation or (I think more commonly) a couple to several to many years later, and over time taking leadership as an alum, volunteering with collegiate chapters and your sorority headquarters. But that is not the only way to be a lifelong member. Don't let your nontraditional path keep you from taking full advantage of your membership.