If her yolk is still attached that deli cup will be best for now. Since it's wrapped around her, it needs to to be tied off and the cord cut immediately (if it has not already been removed). The danger of a wrapped cord is very serious and should be attended to straight away.

Once that is taken care of, I would feed, assisting if need be. The a 6qt shoe box tub with damp paper towels, like you would for any hatchling, will be fine for her.