I came across this article about bi-lingual nannies. It's very interesting. Although it is an American article, I can very well relate to being brought up in a bi-lingual environment.
I am very lucky to be brought up with so many relations around me that speak Cantonese, but I would have loved to be able to learn to read and write at that young age. But I think I was stubborn back then (probably just as stubborn nowadays), I remember crying when I was being taught to write my own Chinese name! I was about 3 or 4 then.
You can discuss this at IBC message board.