Unsecure chicken perches

[RubyandRosie]

I have had Ruby and Rosie about 6 weeks now I think it is. Ruby started laying about 10 days ago and we have had one perfect (although small) egg every day. She is a Miss Pepperpot or something very similar. She is very small herself and looks like she has a deformed beak, so she does not eat as much as Rosie. But otherwise she is a perfect little girl, and very placid and easy to handle.

Rosie on the other hand has grown GINORMOUS!!!! She is from the same breeder (I bought them at a market in France) and looks like a Gingernut Ranger. I thought they must be the same age, as they were the same size when I got them. But Rosie does not lay any eggs at all. She eats about 3 times as much as Ruby and is greedy and aggressive (she will even jump up and bite my finger as I walk along).

Do you have any ideas for me how to start her laying. She is not agressive with Ruby, and even sits in the nesting box with her sometimes as she is laying. But she does not lay herself.

Many thanks for any advice.