I think a better policy would be to reduce the tax burden of a couple with 3 children. This makes working quite lucrative whilst at the same time it creates the flexibility for the couple to distribute work how they see fit, whether this is a breadwinner model or more hybrid.
Pinning this to the mother doesn't work. The policy incentive is to work as much as possible whilst at the same time carrying the burden of 3 children. Not an attractive combination.
Your view is going to change depending if you look at the short or long term.
It has always been trivial to pay a woman to give birth. Incentivizing the creation of productive families with well raised children is the difficult part.
You are of course welcome to disagree.
https://fiscaldata.treasury.gov/americas-finance-guide/feder...
It’s always been interesting to me that healthcare for kids is not as popular as healthcare for old people, such that there is no Medicare for kids. There is Medicaid, but it pays healthcare providers less…why?