I am not an antibiotics expert, @casportpony often helps me out with that. I would not put salt in her drinking water, but would put two tablespoons of ACV per gallon of water in her drinking water for a few hours, then back off to one tablespoon per gallon the rest of the day -
I would irrigate the sinuses with mild saline solution.
I just learned about a gizmo for babies - the nosefrida -
http://www.fridababy.com/shop/nosefrida/
Tossing out ideas here - - - prayers for you all.
Vetericyn spray is fine for my ducks, I reckon it is okay for geese, also. Remember, I am a duck person - so I can share what I have learned from the smaller waterfowl.
Socially, I know geese are a little different, but with the ducks, I have found that helping them know they have a friend, with an unbreakable mirror, a buddy, or my own company - makes obvious positive differences in health and behavior. Maybe - this may sound strange - have you talked to her about how you feel? Just knowing you are conversing with them seems to make my ducks less anxious.