How to teach your children under 5 year to learn foreign language?

My daughter is now three years old and is bilingual. She speaks and understand both English and our national language. I started talking to her in English when she's still a baby. Whenever I talk to her, it's always in English. But my nanny and my mother is having difficulty in talking to her in English so they would talk to her in our native tounge. So what I did is every time they speak to her in our laguage, I would translate it in English. I use few and simple words first so that she can easily understand it and would not introduce new words unless she gets the first ones. I think tv shows and dvds helped her a lot too.