Sitting Hen, how long does it take to hatch eggs this way?

[Dachicken]

Hello, I'm new to chickens. I seem to have a hen who is willing to sit on the eggs. How long does this o'natural process take? Is there anything I need to do? Thanks!

 

[perolane]

21 days. Seperate her from the others...provide food & water....just let nature take it's course!

 

[Dachicken]

Thanks! That helps.

(that's funny!)

 

[Dachicken]

Thanks again. Had 15 eggs, 9 hatched, 7 survived. Now if I can figure out what's wrong with my baby Russian Orloffs...