Float lots of balloons in pastel colors around the room. Use streamers in the same or matching colors as the balloons, and hang them from the ceiling, in doorways and on the mantle. Put up lots of glow in the dark stars and planets on the ceiling of the room the children will be sleeping in. They'll love seeing the night sky when it's finally bed time. Rent lots of "chick flicks" and let the girls hang out watching movies and snacking. Some good choices are The Princess Diaries, High School Musical. Ice Princess, Ella Enchanted, and The Hannah Montana concert movie.
Have lots of snacks available. Popcorn, chips, pretzels, bowls of M&M's, cut up fruit and vegetables with dip and cookies are all quick, easy and appeal to most children. Make a big batch of pancakes, and let your guests make smiley faces on them. Cans of whipped cream, chocolate chips, cut up fruits, chocolate syrup, coconut and anything else you can think of that can be used to make a face. Set up a waffle bar. Make a large batch of homemade waffles, and set up a toppings bar. Include syrup, cinnamon and sugar, whipped cream, berries, nuts, chocolate chips, and cherries. Let each girl create her own masterpiece.