And the egg has a nice hard shell? Not saying if she is a good once a day layer that doesn't take much time off from laying she could not be depleted in some calcium, I haven't read of it causing neurological issues though but skeletal is def one to be concerned about I'd offer her some Calcium citrate[I believe it was
@Amiga] that said her vet rec this form of calcium for her duck. also cal gluconate is another that she rec. I have Runners and Buffs who lay like gang busters and once in a while I'll get a rubber egg and I'll add some cal citrate[capsule I open and put into their drinking water] only takes a few days for egg to be hard again.
As for flush if she is eating and you think getting stronger hold off and see how she progresses during the day. Do you have any poultry vitamins. Might add some to her drinking water.