She should be getting some food, either egg or watery feed, plain yogurt or other mushy food. Are you able to borrow or build a crate of some kind? With chickens over the years, you will always have a need to separate a chicken for illness or bullying. Temporarily placing a friend in with her would be helpful. When I introduce new pullets that are big enough, I always use a pen of fencing, where they can all be close to each other for a week or two before putting them all together. Lowes sells rolls of poultry netting and hardware cloth, and those can be stapled to a wood frame. But dog crates are fairly easy to find or borrow.
