Fixing nesting boxes

[TucksMama]

I have 17 week old golden buffs and two have been laying for a week now. They are using the nesting box but its really small (10" width). It was apart of the coop when i bought it. I would like to widen it for them but I'm afraid to mess up the laying mojo.
When I see them sitting in it they look so crammed. Should I mess with it or just leave it alone?

 

[ChickenCanoe]

leave it alone and add a 12" box
when they start using that, modify the other.
I've had 2 hens lay at the same time in a 12" box so they can hang.