Elizabeth Bailey was a Vault resident during the experiments inside Vault 22. Both she and Marsha Bailey were of unknown relation to Dr. Bailey, though it is suggested that they were his wife and daughter. Elizabeth was observed by Dr. Bailey during her illness inside the common area.
Elizabeth Baily was part of the 2nd batch of people infected by the spores from one of Vault 22's experiments. She most likely became a spore carrier.
Elizabeth Baily is mentioned only in Fallout: New Vegas.