Tea Party
No little girl can resist a good tea party. Set up an indoor picnic by spreading out a blanket. This picnic tea party can be imaginary or real, by using real sandwiches and drinks, or by pretending. Most girls love playing pretend, and are excited to play with the babysitter. You can even add stuffed animals to the picnic and make a whole party out of it.
House
Little girls love pretending and playing made-up games. You can suggest playing House, where everyone is a different character and acts accordingly. There can be a mommy and a daddy, or a princess and a prince, or even a dog and a cat. Playing House works for a wide range of ages. This game could last for hours and keeps the girls amused and happy.
Crafts
It is worthwhile to find cheap art supplies like paper, markers and stickers to bring to all of your babysitting jobs. Most girls enjoy crafting when they are little; they may also like anything you bring that's better than things they already have in their homes. If you don't own crafting stuff, you can easily find crafting things in the house and make that exciting, too. You can make designs together with scissors and markers and decorate projects for mommy and daddy when they come home.
Singing and Stories
Most girls love to use their imaginations. Together, make up stories about princesses or unicorns or rain forests. By making up the storyline and details, the time flies by. Teach them songs you learned in your youth or make up songs together that connect with the made-up story. The girls will think of you when they sing the songs to their parents over and over again.