Do you plan on being the regular, permanent (even full-time) day-time carer of your grandchildren for the first 6 years of their life?
Then don’t stand by while your children hock themselves to the eyeballs for a house and thereby guarantee their need to have two incomes for the next 20 years.
And whatever you do don’t go guarantor because your kids can’t afford the deposit and want to avoid lenders mortgage insurance. Let them live with the consequences of their past financial decisions and learn to live within their means.
Take the time to explain to your kids how tricky it is to balance a job with school hours and 12 weeks of school holidays each year. ( I know kids tend not to listen but it’s essential you try anyway.)
Otherwise you’ll end up being relied upon -doing more care than is fun and more than your ageing body can handle.
Or the grandkids will end up being in before and after school care every day from age 5.
Is that the family life you want for your kids and grandkids? Is that the family life your kids envisage?
If not, do something about it before they over-commit.