There are now 15 eggs (at least!) in Box2. They cover such a large area that it is difficult for one hen to keep them all warm at the same time so we shall be interested to see how many eggs hatch.
There was a brief fight in Box3, but the right bluetit seems to have won as she is still laying eggs in the nest box!
We were curious as to whether both females were roosting in the box overnight as had happened in previous years. We therefore switched the light on briefly at around 9.15pm This is what we saw!
So yes, both females are roosting in Box2 over night.