How old is your children? My son is 8 yrs old, 1 yr ago he is very afraid to speak any English, and I change a Philipphine maid instead of Indonesia, because I want him to have more chance to talk English, and I also joined a playgroup course in British Council (Foreign teacher), and now I think he can understand and are not shy to talk English, so if your children is very small and have no chance to speak English before, I think it is not so useful to recruit a Foreign teacher.