Generally I decide whether or not to support a broody, and if so, choose which eggs she gets to sit on. But following a successful secret nest in 2023, last year and this I have let those who made secret nests carry on. In most cases (viz 4) the nests were predated before hatching, though the broodies (2 different hens) survived. In 1 case the eggs made it to hatch, in the same open outdoor nest location that the first successful one used, though that was a different broody.
Some better than others, in my experience. And they learn by doing and watching each other. One that had secret nests in 2 different locations last year and this, both predated, now lays in a nest box in a coop. It remains to be seen if she'll go broody in a coop this year.