@Lucysmum75
She (and you) are being naive and I don’t think you quite understand what happens in divorce.
If you want to help your sister - you need to stop talking in terms of what you’d like this process to be like and accept reality. And you need to help your sister do the same. It’s an ugly process and she’ll need to fight for what’s best for her and her kids.
Kids are not ‘less important’ in this process. It is just that normally divorcing parents manage to agree child arrangements between themselves. And it doesn’t require court involvement.
Also - there isn’t necessarily a legal framework for deciding child arrangements. Both parents have a right to having their kids 50/50.
So - if your sister doesn’t agree to 50/50 - and they end up in front of family court judge - the judge would be deciding based on what’s best for kids, with a guiding principle that it’s best for kids to maintain relationship with both parents.
And even if your sister’s H didn’t used to do his fair share - it won’t disqualify him from having kids 50/50. Provided that H is able to provide care and is a fit parent.
Kids will also be asked for their preferences, depending on their age.
So - people try to avoid court for deciding child arrangements.
In my case - for eg - my exH also wanted 50/50 originally. I also did most of the childcare as i have been a SAHM. And exH’s job was long hours and frequent travel.
I told him he’ll have to take me to court if he keeps insisting and we’ll have a judge deicide if it’s best for the kids to have a nanny look after the kids while he is working vs them being with me.
At that time - on the advice of my solicitor - i started keeping a journal of what he does with kids, vs me. In case we ended up in court.
Many men start by saying they want 50/50 in the early phases of divorce. Then reality of what it means dawns and they become more sensible.
But for most people - if both parents work and father wants 50% and kids are not too young or high needs - it’s hard to argue why he shouldn’t get it.
Coming back to asset division. Your sister may have a preference to stay in family home until kids finish school. And in some cases it is possible to agree the settlement that way - and sell & split proceeds from sale later.
But - it is only possible if her H agrees to it - end he is able to get adequate housing for him and children while they are with him.
It sounds like you are assuming that your sister’s housing needs are greater than her H. It is not the case. Even if kids spend less than 50% time with father - they still need same type of housing as with mother.
So - say in the case of 2 kids - BOTH parents need to have 3BR places with a room per kid.
In other words - a judge won’t sign off on a deal where wife gets to stay in 3BR house and H rents 1BR - because when kids go to the father (even if just EOW) - and sleep in the living room.
So - financial settlements are complex and need to balance a lot of variables. They do try to make sure both adult parties to divorce end up with similar financial positions.
And, finally - if there is a significant difference in incomes - 50/50 childcare does not have to mean that H doesn’t pay child maintenance. It is possible to claim top up.
All really depends on family circumstances.