How do you share expenses for a child with disabilities when divorced ?

[leadinmypencil]

How does it work?
Maintenance of £300 per month from Dad and then a split of extras such as therapies/ presents.
Mum receives many benefits from authorities, not in England.
These benefits amount to £800/ month plus free electric/household benefit/ transport.
Genuinely asking how it works.Do the benefits matter when it comes to
Maintenance.mum doesn't work as she says she must be available to child and claims carers benefit.Child at school 8.30-4.00. Mild Asd. Dad has child eow and two evenings per week.

In Ireland, there isn't a CMS system. An affidavit of means on both parts determines maintenance. Here it is not uncommon for NRPS to pay little and there is a lengthy process to try to get maintenance. It's so convoluted and expensive, many RP's give up. My stbxh will pay minimum and already at the end of
Our marriage considers study, extra tuition, orthodontics as luxuries. Don't start me on sports clothes and equipment! He will pay basic living costs so I have to think carefully about the years ahead. I will always work as there is no reason not to, my salary is good and most importantly, It keeps
Me sane.

My exH refused to pay maintenance as he said I got enough from DLA (higher rate) and CB. He occasionally contributed to specifics like a residential school trip. Eventually working out exactly what DD cost monthly including share of household costs, he agreed to contribute a small sum of maintenance. He was often either a student or unemployed (supported by new wife and savings!) so CMS would not have assessed much anyway probably.