Join them as a visitor or to study themselves or to work/study until reaching the age of majority if that in fact passes into law ?
There does not seem yet to be any outlook for this change to happen if at all, could be later this year but nobody really knows and whether anyone can apply retrospectively no idea. Maybe others can comment on that given seems rare for minor dependents to accompany a study permit holder when those dependents might be in the plus 18 range which puts them into being college or Uni candidates where they would probably need their own study permit anyway.
