No of course it wouldn't matter if Lucy ate the echinacea nuggets too
With echinacea I tend to give it for three weeks, then take a break for a week or so.
There are lots more things to try, to boost immune and help a rabbit fight off infection. Antibiotics can cause gut disturbance and I don't think strengthen the immune system. I was quite surprised when my vet didn't automatically give them but instead she advised I try other channels. I was very pleased though
That's why I started my other thread about snotty rabbits. It's such an intractable problem, and in so many rabbits too!