If he has parental responsibility for the kids (which he would have automatically if he was married to your friend when the kids were born) then yes, she would need his permission. Have a look on www.britishexpats.com - there have been quite a few people in the same situation. She would also get good info about the immigration requirements for New Zealand. We have just moved to Sydney; it is extremely difficult to get permanent residency in Australia unless you have a skill in demand. I believe that it is easier to get into New Zealand but how much easier I don't know. Brave woman, to even think about it. Having moved here with DH and our three kids, we are really enjoying it but it's not the easiest thing to do and I can't imagine doing it on my own. I hope it all works out for her.