Introducing new chickens can be brutal. If you really can't split them then introduce them at dusk as they won't squabble while roosting in the coop. But be prepared for some bullying during the day and it can take a good week or so for it to settle.
She'll be fluffed up to help conserve heat, she'll be colder on her own as they tend to huddle together for warmth at night.
Worming powder - try googling the product you've got and see if you can get the dose for smaller numbers and instructions. I worm properly twice a year but use Verm-X monthly which doesn't worm as such but puts them off (or something like that).
Can't help with the porridge, I don't do porridge!
a few questions We would like to get 2 or 3 more chickens but I have read that introducing new hens can be tricky and to put them in another run next to the existing hen for a while. But I don't have the facilities to do this. Can I put them all in straight away or will this one get bullied? obviously I am not getting them immediately as i am waiting for ex-battery ones (as she is) so she will hopefully be used to us by then.
Also I went to check on her tonight and she is all fluffed up in her bed. Is this normal? Is she too cold or jis fluffy up part of her bedtime routine?
I have read on here that people give them porridge made with water in the evening. Do you give this to them in their coop or before they go in to bed?
We also got some worming powder with her. How often should I use this and how much do I give one chicken? The doses written on the tub are for 1000 pheasants which isn't awfully helpful
There is so much to learn, but I am so excited, I love chickens so does my collie