This link brings up metal poisoning as a possibility of seizures any chance she could have ingested metal? That is one of my biggest worries when we get heavy rains I find a screw etc that has washed up.
https://www.backyardchickens.com/threads/duck-seizure.283685/page-3
That's sad. Okay Nutri drench isn't going to help with leg issues you need liquid B complex TSC carries one called Durvet and it will say injectable but we pull off the foil pull out the stopper and pull out 1ml put it over a tasty treat just enough she eats the whole thing and gets all the B...