I have 8 hens brooding right now, and 1 more thinking about it. They're standard Cornish, (dark) light Brahma, some brahma mixed breeds, an Australorp, and EE's. 1 of the EE's is broody for the 2nd time this year. I have 2 others who went broody, raising babies right now, a dark Cornish, and a Brahma mixed breed.
I have 4 dark Cornish hens, three have brooded for 2 years, (they're about 3 years old) and the 4th went broody for the first time this year. She's a fierce defender of her eggs. They Cornish and Brahmas are all excellent moms, and my EE hen did very well, too. They take extra chicks easily, too, when I have incubator chicks to add, or if for some reason a chick ends up separated from whoever hatched it. All I have to do is tuck the new chicks under them at night, (I reach in from behind, so they don't peck me) and in the morning they just act like they've always had them. They'll just as happily raise keets and poults, too.