I hate to make a post that has anything less than the most positive things to say.
However, I must also point out that in my experience, some chapters are required to go ahead and release some PNMs after an "Open House" round in which only 10 members meet PNMs for 10 minutes. As an advisor, we ran into this last year. To use nice round numbers, lets say we were told to release 30 women after Open House (prior to Philanthropy Night where the whole chapter recruits in a 30 minute party). There were only 25 PNMs who did not meet our GPA requirement, and we were forced to find 5 more to release. Having not yet met them in a formal round, the only way we could do this was based on their applications. This was very tough to do, and rumor has it that we will be implementing newer, tougher release figures in the next couple of years that will require releasing more women, earlier in the game.
This will make recommendations play an even more important role.
Blair, I would follow the advice of Jocelyn, ISUKappa, and exlurker and get some recommendations. Additionally, get yourself a resume put together and submit that with your application. Even though you might not have been Johnny-Joiner when it came to high school activities, I'm sure you can think of other things that you have done to include on your application and your resume. Employment, Community activities, Fundraisers you may have participated in, Church/Religious activities, hobbies, special interests. In no way should you make ANYTHING up. But reconsider your past few years, I'm sure you will recall things you may have earlier dismissed. I'm really good at this stuff if you need help - just PM me and I'll pull it out of you!