In some cases, the national GPA requirement might be one thing, let's say 2.5. If the local chapter is having scholastic problems of their own, they might only want to take PNMs that have GPA's of 2.75.
Keep in mind that it often that PNMs with high GPAs may turn into NM or newly initiated sisters with low GPAs due to getting acquainted into the Greek lifestyle. That means the older members should (must
) keep their GPAs up to balance out the low GPAs of ALL the other members, new or old.
In most sororities, I'm not sure how fraternities work, you aren't told if you were cut due to specific reasons (grades or other reasons)...so you might just assume it was the grades if all other scores are terrific. My advice if it is 2.0, wait and raise it.. Based on specific circumstances, they may be able to make an exception.
unfortunately, you may be a grade risk the chapter can't afford to take. Or perhap COB might be a consideration since the pool selection is smaller.