My DH has choc brown eyes and is half Japanese and mine are hazel but Izzys are still blue! They have flecks of brown in them - her hair is fair too and mine is dark brown and DH has black hair!!!
There is a site somewhere on google where you enter your familys eye colour including grnad parents and it gives you a % chance of each colour. I think Iz has a 11% chance of them staying blue!!
Some people say that they should change in a few days, others a few months, others a few years so I guess we may notknow for a while!