Agreed, Corid is great - but I had to act fast and didn't have any on hand (and I wanted something in pill form as I prefer it when treating one sick bird - you get a measured exact dose). Since she responded so well and quickly to the Furaltadone/Ronidazole combo, I stuck with it, as generally it's wise to complete the suggested course of treatment (7 days in this case).
I plan to treat the other birds with Corid since it's easier to administer it to a flock that way, even a small flock, as preventative care.