To me, it does look like her nervous system is affected and it's causing her not to be able to perceive her environment clearly, thus causing the "drunk" looking movements. She really needs to be taken inside, and put in a quiet, dimly lit, soft padded area with a feed and water dish provided, after she has had time to stabilize a bit, try dripping a few drops of a poultry vitamin or electrolyte along her bill.
Quite unlikely these birds would be niacin deficient if they're being fed Mazuri feed.