I have thrown several at home tea parties for my girls and thier friends (not for a birthday, jsut for fun) and here are a few ideas:
Use a nice table cloth, cloth napkins, china and real tea cups, you can buy some cheap tea cups at a dollar store if you don’t have any on hand, then maybe you could send each girl’s tea cup home with her as a party favor.
Serve hot cocoa as well as herbal tea, some kids will not like the tea. Good tea flavors for kids include Sleepy Time (Celestial Seasonings) or Chamomile or Mint, or a Chamomile-Mint blend. Nothing too weird tasting or strong. Either sweeten the tea beforehand or be prepared to portion out two sugar cubes each (sugar cubes are more fun than plain sugar and you can use some fancy sugar cube tongs).
For the food I have served finger foods like chicken nuggets, ham and cheese roll ups (roll slices of ham around a cheese stick), fruit kabobs (have the fruit cut up in bowls and let the children skewer the pieces they like onto bamboo skewers before you sit down to tea), finger sandwiches cut into pretty shapes with cookie cutters, popular spreads for the sandwiches include Nuttella, peanut butter, and strawberry cream cheese. I make them open faced and add some berries or raisins or chocolate chips to make pictures or patterns on them. For dessert we have “tea cakes” which are really just cupcakes. You can have them decorate their own if you like as a party activity. I have had a tea party where all the children wore aprons and helped to make all the food in the kitchen with me beforehand, and then while I set the table they ran off to put on dress-up dresses and make-up. They descended the stairs as princesses and came to the tea party. I was the lady in waiting to all the princesses!
You can also have a short lesson on table manners before the tea party and then have small rewards for the girls who show good table manners. Be prepared to reward each girl, but make her earn it! If you do this in a fun way they will like it and really try to show good manners. After the tea party, have a dance in the living room, they will enjoy dancing in their princess dresses! Or you could have them do a craft that involves tea cups, my kids and I made some cute cards once in the shape of tea cups, it was not for a tea party but as a thank you card for their “tea”chers. Here is the link http://familyfun.go.com/crafts/a-spot-of-tea-card-1007634/ You could do it for an easy craft. Just have the cards cut out and then the girls could color them, write in them, and put in the tea bag.
Those are just a few of my ideas, I’m sure there are lots more great things you could do! Good luck!