The Twilight series was not written for nine year olds. It was written for the 15 and up demographic. My suggestion for young readers who want to read it: Become proactive and give her other options.
For example, when I was nine, my mother gave me Jane Eyre. Then Little women, etc, etc.. These are books that have not been made into saucy movies for the BIG screen, but are classics. Your daughter will get the intrigue AND the education that comes from reading the classics. Read with her if possible, bond and talk about the characters. Talk about Literature.
I wrote a blog a while back that talked about the attempt by the merchandising world to sexualize my baby girl...and she was 17, not nine. You will have to be the one standing front and center and offering options...and believe me, this is just the beginning.
Good luck!

Cutest Kid Photo Competition
Submit Your Photos & Win Prizes
The Most Extraordinary Children's Furnishings in the World
Looking for Great Bargains
on Kids Clothes?
100 Award Winning Toys
for Baby and Kids
Mom CEO
(Chief Everything Officer)™
Having, Doing, and Surviving It All!
Mommy CEO
(Constantly Evaluating Others)
5 Golden Rules
Syndication Secrets:
What No One Will Tell You!
Oprah's Books:
Act Like a Lady, Think Like a Man