Hens issues...again

This morning when I got up, Mike said he'd just seen a young fox at the edge of the field and he thought it had just taken one of the hens, however, the hens were all still locked up and when I went over and counted them, there were still the 5 that we have left - the cockerel, 3 hens with him, and a broody in the nest box. He explained what he'd seen and it seemed there was a hen that has been living in the tin hut, sure enough when we went up and searched, in between all the bags of logs, there was a nest with around 20 eggs in it. Well, we've no idea how long this hen has been there and how long she had been on the nest, and what do we do now? 

 Suggested we stick all the eggs, which were still very warm under the broody in the nest box, but when we looked she was already bulging at the seams. The other issue was we couldn't see a strike site, usually a pile of feathers where the fox grabbed the hen. So I suggested we left the eggs where they were in case the hen escaped.

An hour later we went back and checked and sure enough there was the hen, back on her brood.

I have no idea if any of these eggs will hatch under either of the hens, but if they do, then I think we may need to get them segregated this time.

Not a great time for all this t be going on as we have Sam's dog staying with us from tomorrow night for nearly three weeks, and when they called today, she started chasing the chickens...not a good start!