It all comes down to being willing, as a society, to devote adequate resources to everyone, and in particular to every child, regardless of circumstance.
(from experience as a volunteer guardian ad litem)
In the words of a famous poet:
Tout le monde sait comment on fait des bébés, mais personne sait comment on fait des papas.
Make it easy for young men to get and then reverse vasectomies.
Invest much more in the education system and children in general.
Make it easy to get an abortion.
"Shoveling fiat into the household." We had the biggest drop in child poverty during the pandemic (too bad it's temporary), because we gave people money. If you want to limit the supply of dollars raise taxes on the top, that's where all the "fiat" (lol) ends up after just a couple steps.
What I said is much more general: our society must devote sufficient resources that all children have the opportunity to flourish.
Nevertheless I think what you said is a special case of what I said.
More money doesn’t fix terrible parents/households, and they’re numerous to say the least.
All over the world birth rates are falling—even India is approaching below-replacement.
So you can probably move on from your concern, and focus on getting the benefits of economic development to everyone, problem solved!