Immersion is the correct way for the kids...."bilingual" is the correct way for teachers' unions that want to expand their membership and increase their dues revenue.
"BiLingual Education", Illiteracy in two languages.
I knew a family who moved to Texas from Mexico who had a lot of kids. They all learned English in no time. The one who was ten years old spoke perfect English and perfect Spanish without accent. Sounded like a native speaker in both languages. I think age ten is a perfect age to learn a new language. As a person with a degree in Spanish, who is now learning Italian, I think we can all learn a new language at any time. Ciao!