Children education in brussel

I ve posted several times the complete list of private schools in English included. Cheapest English only private school in Brussels for your age range is ace of Brussels and it is actually a very good one for the price too at 14,100, the very cheapest English only for self funding students.

To save money and also to integrate, please consider placing the 8 and 6 year olds into French local and free public school, as you say you're in Brussels, the majority language of 90% of the region. If you choose a well off area of Brussels, the standards of the school and children will be high. That would leave you paying for English for the eldest only.

There is a single school in Brussels which offers English immersion of any depth, 13 hours a week. You might want to plead with the school to allow your 14 year old to join, a small number of English speaking children are allowed into these English immersion programmes. It is at Jean 23 Woluwe school. The immersion programme starts in 3rd secondary from age 13. 

https://www.aceofbrussels.com/http://www.jean23.be/drupal/?q=immersion