Corina,
Take what Mary says with a grain of salt. This is not to say that she is lying, but something doesn't add up here. Wouldn't your Greek Affairs office have let you know if another local was attempting to affiliate with an NPC? If I remember correctly, even if a local petitions one NPC directly, that sorority is still required to pass along the local sorority's information to the extension committee at NPC.
Even assuming what she says is true, times and circumstances change. You and the other founders have taken enormous initiative. I feel strongly that NPC will stand up and take notice. Don't be discouraged! This is not your first setback, and there will be many more to come until you reach your goals. The key is to pick yourself up, dust yourself off, and keep on going!
You have all our support and good wishes behind you!
(PS: Our circle of sisters is always growing in Alpha Gamma Delta. I'd be thrilled if you took a closer look at us.
)