Most of the things I suggest would involve me being the family member, and are hard to perform to anyone else other than me. I suggest dropping an X-box (causes 4.2 on the Richter scale) to wreck her room, thus giving a lesson in humility.
But seriously, I find that putting them in their place works on brats very well. I had one really annoying snob cousin, and through various means she isn't a brat anymore. When she started acting snobbish, I stood over her, looked her in the eye (from 2 feet above) and gave her a little spook. (works best if you're between her and the sun, so you get a good shadow effect going) Just show her that she isn't the boss of things. And when she bits, try wearing a long sleeve fleece shirt, so when she bites, make her bite the fleece, then rip the sleeve out of her mouth. Holy crap, I bit fleece once and ripped it out of my teeth. Less than good. Or, another way to make her stop biting, manuever her arm so that she bites herself instead. It works a little better on 5 year olds, but still effective on 9 year olds.
This would be a prime oppurtunity to send her away to the Snowcraft force, if it was real. THAT'D take out any brattiness. Let her freeze and fight for her life for a few years!
Hope I could help, Jehuty.