WOW!! You have a top-rate broody there for sure! Take good care of her for sure! You can tell she's watching them closely...thanks so much for sharing!
Go to this link:
http://www.the-chicken-chick.com/search?q=broody+hatch
Go about half-way down the page and find the section:
THE QUITTER and the HOMICIDAL HEN
Just because a hen is broody does not mean that she is going to be a successful or dedicated hatching hen. Some abandon the eggs...