My goose vibrate their necks to it maybe from just being stressed. if she is eating grass and that's really the main stay of geese then she is settling down. and I don't put feed and water inside with my water fowl at all. I don't think she could be in better hands. How does she act around you? Kale is another green my gees love but I usually don't feed them greens except in winter since grass they love so much. Remember ventilation is very important with poultry but I'm sure you already know this since you have ducks. Pics when you get a chance, oh and what do your ducks think about this new humongous duck that has invaded their back yard? lolI have her in the same yard, just separated from the ducks by a plastic chicken mesh fence so the ducks at least can't eat her poop (my ducks are classy) So there is plenty of non-physical contact going on. I am also worried about her mental health like you mentioned, it was so sad to see her just hanging around her friend's body, poor girl. She's been a bit noisy, especially for the 10 minutes whenever I leave the duck yard. She is drinking and eating grass, though, so that is a good sign.
I will make a grocery store run for lettuce. And maybe I'll pick up some scratch or corn from the feed store too while I'm out.
I have no idea if some cruel person killed the other goose. It was laying right on the bank half in the water half out. A spot with easy access for humans. Maybe the people who dropped them off in the first place? Dunno.
I will do my best to secure her temporary bedroom and make it predator proof. I'm looking into some really sturdy large sized dog houses on craigslist. I am planning to not put feed or water in there with her at night. Is that OK with geese?
And one more question, she gets a vibrating neck a lot. I know that's sorta normal for my ducks (not very often though, just when they get a little too excited with me), but is this something I need to worry about with her?