Hi Katrina, renting before you make a final decision is always a good idea.
I am not a parent, but have friends who are.
Mijas (pueblo) school is ´average´(do not expect any great shakes from any Spanish state school :(
I lived in Valtocado ´village´(where the small curch/ local meeting hall is for residents.) There is also an Urbanization of the same name on the way to Mijas Pueblo.
It is basically a rural area so most houses spread out.
Ok if you like being in the country and don´t mind driving everywhere. (Coast is only 15 mins away and same to Alhaurin el Grande, but it can feel isolated if you stay at home a lot.)
Property prices vary wildly. Try to get a bargain whilst the recession is still officially on in Spain.
Renting, again haggle for a bargain while you can.
Re Cartama, I have only visited to buy supplies. Seems OK. But maybe check out one of the many Facebook pages for these local areas?
Good luck and hope you are still planning to move out here sometime!
(Many are moving back to the crisis/ lack of work.)
PS I know a fair few people who live in Villafranco too, but I rarely go there. It is also rural.