To be honest I think it's hard to avoid many of the issues around making your child a 'sandwich' generation adult - looking after kids and older parents.
My mum went into sheltered housing at 80 when she was still very active. She went out on jet skis that year on holiday!
Fast forward to 84 years old and she was diagnosed with Alzheimer's following a fall.
She did a LPA for both health and finances - which was a godsend so that's a must. She also expressed where she wanted to live on the form and she sat down with us and went through all aspects of her funeral. Her view was she wanted to make sure we knew what she wanted before she forgot what she wanted! Again a godsend when she died last year as I had everything from readings to hymns to music and flowers on the PC so just printed it all out and handed it to the funeral director. Covid put paid to some of her wishes but she got the majority of it.
But the appointments (she was diabetic and had a heart attack at 82) took a lot of organising. I covered 27 separate ones one year...
Organising carers in her home became an issue later in her life until it became time for a care home. The care home actually took so much pressure off us. She was a council tenant so we didn't have the choice of when/if she went into a home until she really couldn't cope any more. Had we had our way she'd have gone into a home a year or so earlier and it may have prevented the 6 falls she had until she was deemed unable to cope happening.
Some of those things you can't future proof unfortunately but the expression of wishes and getting LPAs in place are a must.
We plan to downsize eventually and, at that point, we'll help DS out with some cash. That way, if we have to spend our house, he'll at least have had something from it. But we're bringing him up not to expect to have the house. Both our mums had Alzheimer's so we're not banking on not having to pay for care. Our house is ours to do what we want with so care home or round the world trip, DS may not get a huge inheritance. We're not going to live a measly retirement if there's money in the property just to hand it on. We'll help where we can but that's the best we can do. Otherwise the care will fall to him and, having been through that, I wouldn't wish it on him. I'd rather have seen mum in a home (which was lovely) earlier and feeling more secure if she'd have been in the position of being able to pay.