I am so happy you found the problem. She sure bounced right back afterwards too. Making up for lost time lol. Bless your heart for keeping at it till you found it!!
You could wrap Her in a towel like a burrito then you can gently open her mouth check under her tongue feel the outside of her face first how does it feel ? Maybe @casportpony knows of a better way to check her out.
Just to rule out something lodged there what about tubing like for tube feeding K to see if something maybe lodged in her throat? Just trying to think of anything that may help this little one
I am a visual person I can read something but having something to see always helps. But hey this isn’t about me.. I just want you the little better better. sorry spell check is my worse enemy.
You looked inside her mouth ? I don’t know what that thing you pulled out of her mouth is. Let it dry and maybe you can figure it out. Doesn’t look like there could be anything In Their brooder the ducklings could have eaten on strings etc?
I noticed she was shaking her butt that’s why I asked about poop did you look at her bottom and feel her tummy area is it normal feeling like the other or hard ? Did they eat anything new today? When did this start is she interacting with the other ducklings?