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I use Valbazen, but had to order it online. It's a lot easier to find Safeguard goat wormer at Tractor Supply (in the US), so that's what I'd recommend. Search this site and there is a great article on dosing, and egg withdrawal. But the short answer is that you do have to toss the eggs for the duration of dosing, plus two weeks with most wormers. Definitely deworm them all if you suspect it has already killed one bird.
Edited by Toddrick - 11/6/15 at 12:50pm
If you saw a worm in the poo with your naked eye, then she probably had a heavy worm load. I'd take care of the worms, even if they aren't the primary reason she died, just because they can be a contributing factor and stress the birds bodies making them more susceptible to other illnesses. If one bird has them then you can bet the others all do, because they eat from the same ground, which is where the eggs are.
Edited by Toddrick - 11/6/15 at 2:11pm