I'm sorry about the pullet.
Just to clarify - she was already having difficulty with balance issues and was "runty"
before she was attacked by the dog correct?
You have lost quite a few birds in a short period of time. Did they have symptoms similar to what the pullet was exhibiting before she was attacked (wobbling/drunk, neurological symptoms, slow growing, etc.)?
I agree, it's hard to know if she can recover since it *sounds* like she was having problems to begin with.
I would try the vitamins and sling to see if that helps her.
What do you feed the birds?
Also, where are you located in the world?
I understand you are working for the farm and they likely will not provide medications/supplements, but
@Eggcessive has give good suggestions of foods that are rich in vitamins you need. If those are not available to you, IF you have a Dollar Tree where everything is $1 check their vitamin aisle. While the pill count is lower than what you get at WalMart/CVS, I have found B-Complex and Vitamin E at the Dollar Tree, so the cost is fairly reasonable if that's an option for you.