Help, My ruby is sick

Yes!  Segregate her.  Then do a search on this forum (Emegencies/Diseases...) for "respiratory".  You should find many posts about it for help!  As usual with these girls...you need to act as quickly as possible.  I'm sure someone will login with more specific info for you, but this will be a good start to get some education on the issue!  Good luck!!

Mix a quart of water each day and add 3/4 teaspoonful of duramycin 10.  Pour it out each day and mix new because it does not last.  Good luck.

x2 I use duramycin 10 for respiratory and it usually clears up in 3-5 days. 3/4 tsp per qt is fine, be sure  it is her only source of water though. You can also safely treat the whole flock just in case, and not have to separate her.
I prefer to do mine individually, only because I hate using antibiotics unless necessary. I don't want my chickens to build up resistance for those times when I really have no other option but to medicate.

I would keep an eye on her droppings and check for worms. I wouldn't deworm unless I saw something, at least not until she was feeling better. Either way you aren't doing any harm using the duramycin now. Gurgling, even if it were from worms,  would likely be caused by a secondary infection and not by the actual worms themselves in my opinion. Keeping her warm, eating and drinking are most important for recovery. Vitamins are helpful too.

Good luck, hope she recovers quickly for you.

Oh your welcome. I know how upsetting it is for some of us to have one of our babies sick.

As for using the vitamins along with. I know it's fine for them to have both but no idea if one would deplete the other if mixed together in water. I usually give vitamins orally or in the food when I'm using an antibiotic. Maybe you can call the company that makes the vitamins you have and ask them?

Dosage should be on the package. If it seems complicated to figure out for one chicken tell me what it says and I'll figure it out for you.