I agree with RiverTam, imageiseverything - and I think you should be encouraging your dd to focus on the things that interest her, not worrying about her appearance.
Contrary to your user name, image is NOT everything. I would say that confidence is everything, and you should be encouraging your dd to be confident AS SHE IS, not telling her that she has to conform to a particular stereotype or image in order to be accepted or popular.
The solution to bullying is not for the victim to change - it is not their fault they are being bullied, it is the fault of the bully or bullies. And it is worth remembering that bullies look for weakness, so they can exploit their power. If your dd were to be bullied about her eyebrows, and you plucked them for her, the bullies would find something else to bully her for - because it is NOT about the eyebrows (and it wasn't about you being a geek, when you were younger) - it is about their insecurities, and their desire to hurt someone.
Teach your dd that she is gorgeous, brilliant and wonderful just as she is. Give her confidence in herself, and enable her to stand up to any bullying.
It would be far better that she should be able to show the bullies that she is happy as she is, and doesn't need to kowtow to them or their demands than to tell her it is her responsibility to change, in order not to be victimised.