No is not true of New Zealand , and even pregnancy does not force two people to marry , that is the choice of couple should that happen .
I can not say it would be normal a English person would not marry a asian because of family concerns as you said by english mans mother , And certainly in New Zealand and countries like Australia there are many mixed marriages and very normal , I was born in New Zealand but lived most of my life in Australia , my wife is Chinese and that is very common to see in many western countries .