All schools teach the same curriculum. However, you'll find the children at Joli-Bois are on average from better off backgrounds, most are from the near area, though quite a few get off the 36 bus each day who get on at Stockel metro, then travel far to get there, they are from I'd say poorer backgrounds. Crommelynk primaire has quite a high percentage of boarding house children who are again from poorer backgrounds, but not all. Ask if you can have the average mark for CEB for the past 3 years and the percentage of those who passed, if you want to compare academics. But if your child is clever, it really won't matter which school so much for them as it might for the parents!
If you're after a sizeable English speaking population, for social life outside school, you won't find it at either primaire, but will at the maternelle of Joli-Bois. If you're not English speaking at home, you might want to find some children who speak the same language at a school, it really can be good, so long as it's not 40% of the school population!!!
I don't think either Joli-Bois or Crommelynck have set enrolment days, they don't fill their primaire classes so it's not necessary. However, Mater Dei will have a waiting list, for that school it is essential.For the maternelle, you need to phone tomorrow 02/762.12.35 from 9am. Cannot see details on the primaire website, ask the maternelle. If you don't phone tomorrow, little chance you'll get a place for the younger one.