Getting dressed to go to an event is usually pretty easy. Most places don't have a dress policy, and unless you are going to the opera you don't have to put too much thought into how you dress. To dress for an Ivy League graduation ceremony you may have to think a little longer about what is appropriate.
Wear the appropriate fabric. Steer clear of jeans or jean skirts. These are far too casual for an ivy league graduation. Also stay away from cotton shirts and skirts unless they are more fashionable than a polo shirt.
Keep yourself and your daughters covered. Allow clothes to cover your body in a modest way without looking too stuffy. Fashion doesn't have to be all about flaunting what you have, but accentuating what you have in a tasteful way.
Put the right foot forward. By avoiding sandals and flip flops, you will be able to make a better impression. Heels are fine, but make sure that they are proper shoes that don't make a flapping noise when you walk.
Stick to the basics. To dress when attending an Ivy League graduation ceremony, stick to basic black or brown slacks, and a simple blouse or shirt. The simpler colors on the color wheel are the best ones to refer back to when you have a problem deciding on what to wear.