>>>Yes. It can be done.
>My daughter-in-law is an example.
>
>How old is she? Issue is that education costs have been rising at 6% over inflation since the 1970s. Easy enough in the '70s and '80s became more challenging in the 1990s, difficult in the 2000s and improbable without support or debt in the 2010s. Inflation adjusted costs would be 15 X as high today as those paid by you or Marcia. It must be frustrating for the young to be lectured to match the Oldsters' prowess by people whose costs were less than 10% inflation adjusted and who also sucked more than $300K in benefits than they put in. The young would be delighted to be given a chance to emulate that, I would think.

I won't disclose her age, but her older son is 19.

In fact it can be done today.
That 19 year old is doing it.
His parents drew the line at going into debt to finance his education (I agreed with that idea) and he's going to a community college -free- for the first two years while working and living home.
His high school grades were good but not high enough to get financial aid at a four year school.
He's on the dean's list at the community college and his chances of getting aid at a four year school during the last two years are pretty good.
He also considered ROTC- with the intent of becoming a Ranger- but changed his mind when he became interested in biology.
He has one huge advantage- he can live and eat at home. He drops in here now and then for a meal.
Lots of kids don't have that. His mother didn't.
His younger brother has much better grades and will probably get aid at a four year school.

The real problem here is that the parents don't make enough to pay the crazy school costs.
Both parents are successful professionals with good incomes but their 401K's have been decimated by several financial crises and they're already sweating about their retirements.

I easily put two kids through first rate private schools on one income.
That's almost impossible today.