Bklynmom,
From the information you've given, it sounds like you're right on track to do the 100 mile ride. Why do I say that?
1. You're "rockin'" on the rollin' hills, and the course has rolling hills rather than the alpine mountains that you're going to do in August.
2. Based on a typical century training program, your mileage and long ride is right in line with where you should be a week before your ride.
Here's a link to a sample century training program:
http://www.diablocyclists.com/RiderT...ingProgram.htm
3. You've been training for 2 months. If you'd started two weeks ago, that'd be a different matter.
I think you can do the 100 mile ride, and that it will give you confidence for your upcoming charity ride in August.
Have fun!
-- Melissa