Viable eggs for broody

[Happy hen lover]

How long are eggs from fertilized ( rooster present) good for a broody hen to sit in. Reason I ask is I have a BA that goes broody twice a year and I have no roosters.
I gave a rooster and 2 hens to a friend last year. I could get fertile eggs quickly from them . Would those eggs be okay to go under her if 3 days old so I can accumulate a few ? Or do they need to go under her right away.?

 

[JacinLarkwell]

Up to seven days is usually okay

 

[Yardmom]

Hens allowed to collect and set on their own can have eggs at least 2 weeks old when they start to set. I allow my ducks to do this and they have hatched those eggs just fine.