The question presupposes that there is choice and that you can't save both but only one and it is up to you which one.
I will save my own child every single time instead of my wife if I'm forced to choose. That's what she would want, too. I'm absolutely 100% certain of that. To me, to think otherwise is completely incomprehensible. This is not about the marriage or anyone's status in the marriage. It is the most natural thing in the world to want to save your own children first and your spouse second. The children are not part of the marriage. The marriage is between the adults. It is instinctual to want to save your children first. Your children are your flesh and blood and the future. Your spouse is another adult family member and not even related to you. It is the human thing to do to want to protect your own offspring at all costs.
In fact, any proclamation to the contrary is suspect on multiple grounds. First of all, it smacks of a tendency to try a little too hard to convince oneself or others of one's love for one's spouse. I've seen women go to considerable lengths to display their love of their spouse to the outside world only to dump them a short time afterwards. Secondly, if it really was the case that a woman would save her husband in fire instead of his child, I wouldn't want to be that husband, in all honesty. Having a child of yours die is one of the most excruciatingly painful things that can happen to you and will in all likelihood ruin the rest of your life. Knowing that my spouse chose put me through that instead of saving our child and let me die instead would cause me to lose my trust in her for good.