Broody hen drama - suggestions please!

Having just stopped retching over the smell, I thought the most sensible thing to do was ask for suggestions.

I have a broody Silkie sitting on eggs due to hatch on Sunday. I brought her into the house after a fox attack on what I thought was a secure run last week, and she has been happy in a cardboard box in the utility room. (Electric poultry netting is being put up round the run this week, so when they hatch she can go back out.) A couple of days ago there was the most awful smell, so I inspected the eggs to make sure one hadn't gone bad, and they were all fine. This morning I was woken by the loudest chicken shrieking, and thought the fox was back and went running outside, only to find the rest of the birdies safe and sound, and the noise was coming from the hen in the house. She had done the most enormous smelly runny poo all over the eggs. I know broody hens do big smelly ones, but this was like nothing I have ever seen from a chicken - if I didn't know better I would thing a little cow had been in there!

I gently wiped each of the eggs with a dry tissue, but there is still pooey residue on them. I don't want to wash or handle them too much, as I said they are due this weekend. But I am now very worried that the poo will kill the chicks.

Is there anything at all I can do? Am I being paranoid? At day 17 is it too late to candle, or should I just leave them alone and hope for the best? Answers on a postcard!

I really hope the eggs are OK, as the daddy was the bird who was killed by the fox, so there will be no more of those eggs.