I'm sorry for your loss. Did she aspirate or choke? She may have been so sick that any stress just put her over the edge. Here is some information about necropsies and poultry labs.
http://www.usaha.org/Portals/6/StateAnimalHealthOfficials.pdf
http://www.metzerfarms.com/PoultryLabs.cfm
https://www.backyardchickens.com/t/799747/how-to-send-a-bird-for-a-necropsy-pictures
http://www.usaha.org/Portals/6/StateAnimalHealthOfficials.pdf
http://www.metzerfarms.com/PoultryLabs.cfm
https://www.backyardchickens.com/t/799747/how-to-send-a-bird-for-a-necropsy-pictures