People seem to be missing the complexity of caring for a child with SN, tbh.
I've ended up completely giving up on any sort of career, as I have 2 of them. Both school age, now, youngest shortly to start secondary school. Even now, I often spend time sat between them (they hate each other and can't not fight), when they're both home and frantically dealing with the laundry mountain, fixing stuff they've trashed, ordering in supplies of stuff they need etc etc, when they're at school. We have the appointments carousel, which is, thankfully, less intensive, these days. Constant meetings with schools. Time spent educating myself on SEN law and building a case to get DS1 into the school he's in now. DS1 is in an LA SS from September, but the wrong one, as far as transport is concerned (but absolutely the right one for DS2), so I'm facing 5 hours a day commuting on the bus until we can move to somewhere where the bus journey is more manageable or we can tag onto some other transport for an existing fee (moving within free transport range of the school has turned out not to be feasible, partly due to where DH works now and largely due to where he needs to be able to travel if he does lose this job).
DH actually earns a decent wage, well above the local average and not far short of HR tax paying. he has marketable skills but some degree of specialism due to seniority. Despite the good salary, for the region, which enabled us to pay outright for the house we bought (not much more expensive than the apartment in Wales, at the time and only worth twice as much now!) the boys have such profound SN that the receive a level of DLA that puts us in a bracket where we are still entitled to some Child Tax Credits. Of course, we'll lose all of that, when we do move out of the sticks and get moved onto UC, but, considering there are 13 weeks of school holidays per year, on top of all the term time stuff, many people have no choice but to be in that bracket. The only people who pay HRT in the company that DH works for are the directors.
And the Op is in a situation where her DS is 4 years old. DS1 was at his most settled ever at 4 years old. He already had a diagnosis. He then started reception and it all went to shit. His statement was tightened up and things improved, until he started year 1, at which point he completely freaked out and by Christmas was unable to attend school full time.
It's never cut and dried. A lot of parents of kids with ASD end up home schooling because their kids simply cannot cope in a school environment. Are they going to be scolded about being short sighted about pensions, too?
And, TBH, DH has paid a fuckload into various pension schemes, over the years and none of them are going to leave us rolling in it, on retirement. one of those was equitable life. Bye bye to that money.