We are an English family living in France. Our children are being brought up to be bi-lingual. They speak French exclusively at school and speak English exclusively at home. Is it difficult? Not really!
It’s amazing how adaptable children are and how quickly they learn to cope with switching from one language to the other. We’ve never made a big deal about it and neither have they. James found his own way of asking whether he should be speaking French or English when he used to ask “Mummy, do they say hello or bonjour?”.
When we first moved to France with our children in 2004, we did consider whether it might be better to try to speak French at home to help the children adapt at school, but to be honest, our French really wasn’t good enough and I think it would have been more of a hindrance than a help.