I pledged an NPC sorority before joining Nu Sig, and had a really awful experience there. My mom was understandably weary when I told her I wanted to join another organization. I just kept reiterating the positives, explaining that it would be different this time. She wasn't enthused, but I joined anyway, paid all my dues myself (that way she couldn't say anything otherwise...) After a few years, she realized that I had taken a leadership role and that I had changed for the better.... She still didn't understand until she became the VP of her teacher's Union... NOW she gets it!
my advice: pay the dues on your own (if you really want it), showing her that you're capable of making your own decisions...
Reiterate the positives of the org, philanthropy and community service, tell stories of times when sisters were/ are there for you and as an academic support system as well....
also explain that the meetings and other events are imperative the structure of the organization... I wasn't very involved in anything until joining my group, so explaining my knowledge to my parents helped them feel more comfortable about my activities.
(i believe someone already said a lot of things )
Also, invite her to visit the house, meet everyone, etc.
