I went back to work 12 years after becoming a SAHM. I now work in a school. But I had been doing some voluntary work - just an hour or two a week and often in the evenings when DH was home. I had also been a parent/reader at his school for a year before I got paid employment. I knew I wanted to work in a school for the holidays etc so volunteered in the school to get that on my c.v.
I also started a small craft business on line during that time, mainly because my mum had dementia and I needed to take her to appointments etc. That meant a job with strict hours wouldn't work - no one will let you have that much time off work when you'd only just joined. So I worked with what I could do and started a little business to keep myself sane. It isn't related to my current school job in any way at all.
What it gave me, though, was up to date skills in Excel, Word etc., Accounting knowledge, design skills (I designed and built my own website with no prior knowledge or computing experience) and softer skills like customer care and negotiating on things like packaging etc.,
All of which helped me when I applied for my current job.
I agree that the 'time management' aspect of being a SAHM isn't a great thing to put on a C.V. A working parent also has to do time management so you're looking for something different. Something that shows initiative and an understanding of what an employer may look for.
Helping to fund raising at the school, becoming a school governor or helping at the local food bank. A local faith group (church, synagogue etc) always need volunteers in the office. Our local church has people to help with social media or updating the website. They've just had a volunteer starting to put together a Powerpoint presentation library as so many services (Sunday service, weddings, funerals etc) are still being shown remotely that the vicar wanted appropriate 'holding' photographs and music for people who joined the remote service early. All of those skills are transferable and valuable to an employer.
Even using Excel to keep a track of the family budget shows you know the latest packages. It's finding ways to become up to date with your skills. A lot of recruiters used to offer updating on PC packages. I don't know if that's still the case, but there's nothing to stop you open up Excel (or Powerpoint or whatever) and YouTube and teaching yourself. My DS has taught himself keyboards with YouTube - so everything's available!
It's the ability to speak with confidence and knowledge about packages that shows you can use them on your c.v.