Ok.. not much to go by but will do my best for you ok
Think your birds have a mycoplasma... infection
They need Tylan 200 injections.. for 5 days
Also the bird that is sick now.. could be a form of Rickets.. so make up this formula and feed it to the bird
Don't allow it to just lay on its side... lungs will fill up with fluid and it will drown
Make up a sling for the bird .. here are some pictures that you can look at
I also need to know the droppings.. what they look like.. color .. consistency of the dropping.. white caps how much etc.. be very graphic please
As they could have Coccidiosis... and if so the Rickets formula is a no no
*thats what someone wrote on the website, So it sounds like you might have to weight for the tylan. Other wise id keep her in the house and hope for the best, try to get her to eat and drink.