If it was the plastic BB's, that's completely different from the lead or steel. If it was a plastic BB, I'd probably look at other possibilities that caused her death, unless her gizzard was blocked. I'm sorry for your loss
Did she ingest the BB or had she been shot? Where are you located? A lot of birds are molting right now and that can really bring a bird down. Are any of your other birds loosing feathers?
@aart
@azygous
@Wyorp Rock
@Eggcessive