Maybe your sister meant she would take care of her husband needs first. Like someone said the love you have your husband and children are not the same.
If I had to save my husband or child in a fire , I would save my child first.
I think the constant needs of the children are a liability to my marriage, but my marriage is an asset to the children. I guess really we love and care for our children as a team and without total love and support for each other we wouldn’t be as successful in that venture.
The kids get our time first every day, but I certainly make a concerted effort to spend adult time alone with the wife having nice meals and uninterrupted conversations and drinks. And in 20 years I hope my kids have left the nest and we’re enjoying each other full time.
Do you love your parents more or your spouse? Your siblings or your grandchildren? Different people occupy different places in your life and they are like apples and oranges… they fulfill different needs.
I can’t figure out how to quantify love for spouse vs love for the children to even be able to answer which is “more”. It’s different. My love for my partner is different to my love for my daughter is different to my love for my son is different to my love for my father is different to my love for my mother is different to… Etc.
On a practical level, the children are needy, demanding bags of need and demand, and we sacrifice some of our “us” time into satisfying those needs. Eventually the nest will be empty and they’ll be pouring themselves into their life relationships and their own children/careers/life focus, and we’ll be more about “us”, so that needs to be maintained and tended and not lost through inattention. There’s no “love more” or “love less”. There’s just divvying up our finite allotment of time as best we can according to need.
And life threatening situation answer: save the kids. I’d never forgive him if he saved me over the kids, and I don’t need to ask to know he feels the same if the situation was reversed. If nothing else, they hopefully have 30+ more years of natural life ahead of them than we do so it’s more bang for your buck 
As someone who has lost their spouse, I’ll wager my hell against yours any day 
That might not happen if they don’t forgive you over choosing them, some parents are like that.
Pretty much everything** Skald** said.
The needs of the kids come before the wants of the partner, because kids are small and needy and grownups have to know how to wait. But they aren’t needy all the time; putting the child’s wants before the partner’s needs can turn into a problem for everyone. And one thing children need is a stable and happy set of parents, if at all possible.
These things are so different, I feel like there should be different words for them.
It’s also very circular. A lot of the things one does to demonstrate one’s love for one’s spouse and the things that demonstrate one’s love for one’s kids all blend together.
I bet a lot of the people who might pick spouse as the most loved, and those who pick children as the most loved in theory would actually make the same choices in similar scenarios in reality.
When the children are grown and living their own lives, what are you left with? A spouse who may or may not resent the fact that you “loved” the children more? Because of the natural demands of children their needs often have to be put first, but the spouse needs to feel that they would be put first if it were possible.
IIRC, there was a thread on this recently, and a clear majority chose the spouse.