Duck-Duck-Goose
It's hard to go wrong with a classic game of duck-duck-goose. Everybody sits in a circle and the child who is "it" walks around the outside of the circle, patting each person on the head as she passes and saying either "duck" or "goose." The person dubbed as a "goose" must jump up and chase "it" around the outside of the circle. "It" tries to sit in the goose's seat and "goose" tries to tag "it." If tagged, "it" goes again; if not, the goose becomes "it." There is no official end to this game, you just quit when you're ready to be done.
If you're having a themed party, change the words of the game from "duck" and "goose" to something more fitting. For example, it could be "Peasant, Peasant, Princess" or "Duck, Duck, Turkey."
Freeze Dancing
It's hard to find a 4-year-old girl who doesn't enjoy dancing and this game is a good one because there are no winners or losers. Just gather the girls in an area where they're free to move around and dance. The rules of the game are simple: when the music is on you're free to dance, but when the music stops you must freeze.
Again, if you're having a themed party, choose some music that matches the theme. Choose princess songs from your favorite Disney movies or Christmas music.
Bubbles and Chalk
It's hard to go wrong with some bubbles and chalk to entertain your young girls. Be sure there is plenty of space for them to chase around their bubbles or doodle to their hearts' content. These activities can even be part of the party favors that you hand out to your guests.
Treasure Hunt
If you have some type of gift or prize you'd like to give your guests, a treasure hunt is a good way to distribute them. Hide the objects around the room and have your guests scurry about trying to collect the prizes. At the end, you can put them all in one main pile and divvy the prizes out accordingly.