my 8 mo SF girl went broody last month(which I NOW understand what truely broody looks like) and we discouraged her and seemed to work. the last 2 nights(and during day) shes been hanging out with the 10 week olds(9 of them) and last night she was actually on top of them on floor. they won't roost yet(am improving their inside area). suzette,the SF girl, normally is a little stand-offish of the other chickens and at night DOES roost but this started 2 days ago ad wonder if she thinks shes mom to these smaller chickens? that would be the best case scenario as if thats not the case I would worry she is ill. I would possibly use her as a brooder when the current"babies", black australorp pullets and 1 cockerel, are old enough and start laying eggs.