Because Grandma had her mom watch her kids so didn't spend $14,400/year on infant care, and her mom had time because she got fired from her school teacher job the day she got married!

Today's mom, on the other hand, moved to San Francisco to get her data scientist/devops/whatever job (there were not any in her area of northern Minnesota and she kind of liked CA after going to Stanford) and Grandma doesn't want to move to CA because it's going to fall into the ocean, you know.

Also because Grandma can't afford to live in CA on her social security pension.

Because california is fighting the climate change by taxing her to death that would otherwise affect all those never will be born babies.