Fox wipeout - only one hen left!

For now I'd bring her inside and put her in a dark area so she can calm down. There are many serious complications that can come with stress in chickens, she could become egg bound or sick from all the stress so its best to get her somewhere safe and warm until you have a safe environment prepared for her. It may sound weird but lavender and rosemary are good to put in her nesting area for now to help induce a relaxed state. Considering that she was the only survivor I would check her thoroughly for wounds as its strange for foxes to leave behind any food. Having been through something traumatic could also make her depressed so be sure even when you bring in the new ones that she is foraging and not roosting alone all day. Be sure that she is eating and drinking as well, chickens can become withdrawn after events like this. Best place to keep her is in a carrier in your bedroom or living room for now so she will be around you rather than alone. I hope this helps and I really hope your baby recovers.

I almost forgot! As far as prevention we found huge success in using motion sensor lights to startle predators along with burying two feet of chicken wire around the coop for safety. Foxes can be very cunning though so its best to install a door to your indoor coop to close at night and be sure the structure is made of strong material. We have also had hawk issues though so I recommend making a roof to your coop out of chicken wire to be sure. Check daily around your coop for any signs of digging though and if you come across it just refill the hole. It's gross sounding put also occasionally dumping urine around the enclosure can help deter them. I really hope this helps you.

I agree with Minalikesyou!

We've had that problem too. The fox wiped out our whole flock. Grey foxes have retractable claws and can climb right over a fence. I thought they were nocturnal but once I came home to the fox grabbing a hen in the middle of the day! (I chased after him and he dropped her, shaken but unharmed!)

Close the coop at night, and maybe try one of those owls farmers use in the barn. Do you have a dog? Let the dog around the coop and his scent may deter other predators. Unfortunately, once the fox knows where the flock is, he remembers. You may want to trap him.

Thank you very much everyone!
She's now got two young companions (both about 20 weeks old), and I'm thrilled because she made it clear to them immediately who's boss! I feared they'd possibly make her even more nervous, so I'm very glad about the outcome!
I've been spending lots of time with them, and she seems to be foraging just fine - she goes into the hut a little earlier than the other two, but I have a feeling that's more to do with the fact the younger two were indoors 24/7, and only had light when the shed door was open (no windows), so they're probably still learning about when it's bed time im guessing!

So happy for you and your hen!