1. I am in California and active member of MTAC. Yes, in California, there is a CM test. We share the same syllabus with our neighbor, Nevada and Arizona too. Other than these states, I am not sure what kind of test they have.
2. Peggy ODell is a good book, and I am using it right now for my students who is taking the CM test. However, Snell and Ashleigh is also good, but they are not arranging their materials according to CM test, thus, I find it harder for me to use it because I have to prepare my students for CM test. In short, both of them are good, if you want, you can buy both for your daughter. I use Peggy ODell more just because it is arrange by syllabus of CM. I found that Snell /Ashleigh has their strong point in explaining things too.
I also use Basics of Keyboard Theory by Julie McIntosh Johnson for CM students and this series is arranged according to CM syllabus too.
Also, you need to make sure that you put your daughter in the right level of theory according to her performance part. However, if she never learn theory before, I would suggest that she start from Level Primer of all these books
Just some suggestions, hope will help!!
English is my 4th languages, please excuse my grammar. Thanks