Look very carefully for a string or a hair that could be wrapped around her tongue. Granted that is not her only injury, but that is a common reason for the tongue to swell. Also try to clean out her mouth and beak of mucus, dirt, blood, etc. when she is able to breathe, then wipe her face off with a soapy warm damp cloth. Where are you located? Could she have been stung by something, or is most of this from a fight or attack? Please answer.
We have had a few others with hair or strings wrapped around the tongue that have swollen and almost blocked the airway. Insect stings, snake bite, or an injury should be considered. How is the chicken doing?