School for a international English speaking 13 yrs kid

Dear All,
I am an expat working in Brussels. I have a kid who is 13 years old now. I do not want to send her to any local school because of the language problem. She knows french but still the medium of instruction is preferred in English.

All the international schools are very very costly ranging up to 30.000 euros per year.

How can I find a school (at least a bi-lingual one) which is moderately charged?
Is the option of home schooling OK? Do we have anyone here who have tried home schooling?

Please comment.
TIA.