On that linked thread people are talking about the age at which strange men stopped hassling them - if that's invisibility it's a good thing! It's a bloody strange and twisted take on the word though!
There is a kind of invisibility some people suffer from - they are overlooked, not served at the bar/ in any non obvious queue service industry situation, overlooked generally for promotion, for invitations, just generally not noticed. It's a timidity about them though - and yes, women who used to rely on looks for confidence probably experience it as part of the aging process, but men who are mostly socialised to just intrinsically believe that they are important or women with more general confidence probably don't.
I used to be pretty ish in the way pretty much every confident, slimmish young woman is, and am less so now I'm in my mid 40s. I don't seek male attention, I wear a wedding ring, I don't get leered at in public or from "men in vans and cars" [boke] like I did in my teens and 20s but that's good . I wish no teenage girl had to deal with that misogyny and objectification.
I don't feel invisible in any way, but I've never been shy or retiring. I do tend to be remembered - it's not necessarily a good thing! However invisible I don't think I'll ever be. My mother's in her 70s and quite - erm - marmite. People remember her though. Some find her charming, some find her overwhelming or a bit odd, but not invisible!
I don't know what to suggest if your feelings of invisibility are upsetting you except to get out into the world more. Fake it til you make it with confidence - talk to people, volunteer in a context you can (toddlers group? Primary school? How old are your kids?)
I was mostly a sahm for a few years, (though I always taught a few evening classes which, btw, makes you incredibly visible in the wider community) and although it felt very worthwhile when I had children under 3, especially when they were all small, I had a bit of an existential "what's the point of me" crisis when the youngest started preschool. I'm prone to this - previously left a very well paid job that didn't contribute anything to society for similar reasons - if I wasn't doing it ten other people would bite the employers hand off and it was utterly pointless on a human level, what was the point etc. So I went back to work - in a socially useful job - and began studying for a further professional qualification when the youngest child was nearly 4. This has increased my self esteem and stress levels pretty much equally...
If you're unhappy, do something about it. You might feel better if you worked doing something you see as valuable, if your kids aren't very tiny.