Elizabeth Bailey was a Vault resident during the experiments inside Vault 22. Both she and Marsha Bailey were of an unknown relation to a 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 Bailey was part of the 2nd batch of people infected by the spores from one of Vault 22's experiments.
Elizabeth Bailey is only mentioned in Fallout: New Vegas.