It's normal from what I hear. My dd is 9 too and I swear she thinks she knows it all and argues with me every chance she gets. I'm about to ship her off to boarding school. lol
It is normal. My dd is 11. It does not get better. Her dr said it is normal part of puberty and that girls start experiencing pms symptoms around 8 or 9.
My 9 yr old is starting to get some attitude, too.
i'm sure it's normal.
Get used to it, it gets worse every year until college.... :(