1. Show up to your meetings.
-If you don't show committment to them, then they don't have to show it to you.
2. Girls are raggedy...get a non-involved 3rd party to sit in on discussion between you and the VP.
3. You can't "punish" anyone when they've already started with what you began. It's growing, with or without you. So suck it up and show up to see what's going on.
I hate to say it hon, but you're not taking the "high road" on this by wanting to "punish" them. True, what your co-founder did was wrong, but then again, if you said was detrimental to the sorority and she believed it needed to be said than she did what she thought was right.
PS. Include some more info, sounds too one-sided so far.

PSS. I take it you're "DeLuna"?
Zeta Psi Pi
Hmm..sounded good here...