C.T.
Hi T. - you might consider doing a web search on the books looking for different Christian media reviews of the series. Focus on the Family does book reviews on their website. Read one of the books first yourself to get a comfort level - it doesnt sound like they take long to read. You could also discuss with her teacher about alternatives if you dont allow her to participate and if she will be the only child on a different course.
If you allow her to participate, perhaps consider reading the books along with her so that you can discuss areas that concern you or set up a teachable moment.
There are a lot of great books out there that are written by people who are atheists or that have themes contrary to a Christian worldview. It doesnt mean that they shouldnt be read. Voltaire, Camut, Sartre and Rand are prime examples. The important thing is to discuss with your child what she is reading and help her to build the skills she needs to analyze and compare what she is reading to her belief system. The Bible itself is full of stories of people whose ultimate quest was for power.
Taking her out of the program is a ridiculous idea in my opinion especially since she can opt out of this particular material.