I have one of those broodies, a Salmon Faverolle. She is on her 3rd broody state since thanksgiving. She was broody at Thanksgiving, we gave her eggs, they all disappeared(still clueless where they went to) except the duck eggs. Only one developed, and when it pipped I peeked in the hole and it was all yellow, it broke its yolk. It was still alive so I snagged the egg and helped it, but it died before I got the shell off. she broke broody the next day. And molted the next week. In January she went broody again. I kept evicting her from her nest. One day I threw her into the yard...and she landed right in the ducks half frozen pool. She broke broody again. Now, she's been broody for 2 months. She's sitting on a duck egg, and as I didn't think anything would come of it didn't think to mark how long she's been on it. It's been 3, maybe 4 weeks, It's due to hatch soon. I'm prepared to snag the chick from her if she wont take care of it and raise it inside.
In between broody she lays maybe 2 weeks and molts. She was 2 weeks old Easter 2011, so is just a bit over a year old.