Ten screaming 9-yr-old girls!

My daughter's birthday party was last night. This was her first party with friends at our house, and I was looking forward to it more than she was. I think she was excited and nervous at the same time. We made pizzas, crafted pumpkins, played some fun games and even had chocolate fondue. Everyone had a really great time and there was absolutely no little girl drama. The only hiccup were a few girls with very big personalities and Hannah went to her quiet zone. I asked her what was wrong, but she wouldn't tell me. She's very comfortable being by herself and when there are too many girls around I think she starts to feel lost. I tried to pull her out of it, but once she is in that mindset it's usually best to leave her be. She will return to playing in her own time. No need to make a mommy-daughter scene during the party and try to force her to have fun. It frustrates me, though, to plan all this so she could have fun with her friends and then she doesn't want to play the games, or do the crafts, or even eat strawberries or marshmallows from the chocolate fountain that her dad brought from his work. She started coming out of her shell as the girls were leaving. As each one left, she became a little more outgoing, shall I say a little more the center of attention again. Afterwards, she said she had a good time, but next year maybe we could only invite two or three girls.