Almost never but .....
One time I had a few eggs under a broody hen and more in the incubator. That's the way I usually do it now. If something goes wrong with one of the incubations the hen still gets chicks to raise. Only two eggs hatched under the broody, both red chicks. These hatched a...
I don't know how many eggs you have or if you have candled to see if they are developing. Some of that is curiosity but it might help me be more specific in my response.
Each hen is an individual. Some broody hens will accept practically any chick regardless of age or how long she has been...