These are the schools in Ewell until secondary:
Wallace Fields
Infant and then Junior Schools - Outstanding ofsted reports. Massively oversubsribed so you need to move very near it, surrounding area is lovely, mainly 3/4/ bed detached properties that will set you back a fair bit!
Ewell Grove
Infant school, again outstanding. Only problem is then the children move again at 7.
Ewell Castle
Private, mixed until 11 but boys can stay on until 18.
St Clement's Primary
Catholic, good ofsted, hear good things about it.
Several more options both private and state as you move more towards Epsom.
Secondary wise you have as 23balloons said Glyn for boys and Rosebery for girls, both good results wise. Nonsuch is just down the road, a good grammar school for girls and there is Sutton grammar for boys. Plus some not so great mixed 'comps' but plenty to choose from.
All in all schools are good and it is an excellent family area I think.