It depends on the intelligence of the parents. My niece was home schooled by very intelligent parents, both exJWs, he's a computer programmer, she taught herself to speak Japanese. My niece now has a bachelors degree, a masters and a PhD.
My sister's children on the other hand were raised by JWs and haven't done so well. My eldest nephew is very bright and is doing 'something in computers' which could mean data entry for all they've told me. The other two nephews as far as I know are still living at home, they're in their thirties, not sure if they even have jobs. I haven't seen them for fifteen years.
My niece did struggle with sixth form college at sixteen to do her A levels because she hadn't been socialised by school but she seems to be very confident now and she works in London.