First thing is make sure your daughter is getting plenty of Spanish lessons and learning opportunities before you move out here. Spanish courses, loads of Spanish CDs, etc.
At 9 it starts getting difficult to pick up the language.
In normal Spanish fashion she may be put back a year too if they feel she will struggle in the lessons.
The Manilva school has a better reputation than the one in Sabinillas. Teaching methods are probably not what your daughter is used to. Here it is very much about memory and "just learning", without too much requirement for creativity.
There are English kids in most classes, normally 2 or 3, and they do tend to stick together.
You may also want to consider the new school, I think it's called "Micandil" which is near Coto Real, although I think there are a huge number of expat kids in those classes there.
Our kids are very happy in the school in Manilva, although they have been there for for the past five years since they were 3.
Best of luck with it.
Justin