I've had this female since last year. she never laid when 3 of the others did. She is healthy. I noticed she has been trying to mount the other girls and in the case of the video the male. Would you put this down to thinking of nesting or would you just say a dominance thing? I know the male has mated with her many times. Just she didn't show signs at all last year even when separating her from group. Hope the video helps
https://youtu.be/Uv_V-1nHzM0