Vitamin b deficiency or Mareks

[Brahmachicken240]

Try it and see if that makes a difference.
Did your vet perform a fecal float to look for worms?

Since you are in Ireland, likely you would have to get a script for most dewormers (I think) so the VermX is probably what they want you to try first(?)
I know some use Flubenvet or Levamisole so these may be what they give you if you need something else.
Don't know if you have ever run across this, but PoultryKeeper.com is based in the UK, you may be able to find some of the products they recommend on there. https://poultrykeeper.com/general-chickens/worming-chickens/

It was just a phone call and he recommended it to me.
She seems to be getting heavier every day now, I haven’t weighed her but she feels heavier than Some of my other hens... maybe it’s because she’s getting all that food to herself. I also forgot to mention She was on the bottom of the pecking order and she was a bit of a runt, the smallest of all her siblings. She looks to have grown a lot while not being able to walk.. . Also would it be better if I gave her the b complex tablet by mouth ? Just to make sure she’s getting enough.

 

[Eggcessive]

The B complex can be crushed onto some food 1/4 tablet daily, or put in the water1 tablet per liter of water.

 

[Wyorp Rock]

It was just a phone call and he recommended it to me.
She seems to be getting heavier every day now, I haven’t weighed her but she feels heavier than Some of my other hens... maybe it’s because she’s getting all that food to herself. I also forgot to mention She was on the bottom of the pecking order and she was a bit of a runt, the smallest of all her siblings. She looks to have grown a lot while not being able to walk.. . Also would it be better if I gave her the b complex tablet by mouth ? Just to make sure she’s getting enough.

She may be gaining weight if she is by herself
Sometimes the runty or low pecking order girls don't eat as much because of stress or even from being chased from food.

I don't know how many chickens you have or how you feed them, but I've found that having several feed "stations" works best (for me). I have food spread out a bit more and top hens (bullies) can't control all the food that way.

You can give the B-Complex how you wish - directly in the beak, crushed over food or in the water

 

[Brahmachicken240]

Outside today
She’s growing rapidly.
But sadly still is finding it hard to walk

 

[Brahmachicken240]

Here’s a video

Other hens all look happy

 

[Eggcessive]

Glad to hear that she has been putting on weight, but it is too bad she is still having such a hard time getting around. She might not get any better, but she still could have a good life even with her problems walking. Sometimes we never know the cause of some problems until a necropsy can be done. She might have suffered some sort of injury that caused some problems with her leg nerves.

 

[Cragg Klefor]

She is so beautiful
While she is managing to get around, once the others don't pick on her, depending on your end goal... she could still have a good quality of life as she is!
I have a little chicken who can not walk. At all. I would give anything to see her as mobile as your little one. Just to offer some perspective.

 

[Wyorp Rock]

Here’s a video

Other hens all look happy
View attachment 1636365 View attachment 1636366

Bless heart sweet heart She is so pretty! I do hope that she improves, but this may be as good as she gets. It's good that she is gaining/growing. Hopefully as she gains more weight her legs will still be able to support her - I'm sure you're concerned about that, but only time will tell.

Glad to see all your other ladies are doing well! They do look happy - they are all just lovely

Thank you for the photos and video!

 

[Brahmachicken240]

Rooster booster arrived today. I put some in everyone’s food.

 

[Eggcessive]

What a trooper. She reminds me of my grandson and some other kids walking with cerebral palsy. As long as she can can get to her food and water, she seems to be able to grow and develop.