Dr. Olivette was the first known overseer of Vault 81, and was the only member outside of the scientific inner circle, to know of the vault's underlying experiment.
When Vault 81 was first built, it was designed with two parts: the residential sector where the vault dwellers lived in ignorant bliss, and the hidden research sector where scientists would study in hopes of creating a cure for all of humanity's illnesses. Dr. Olivette was the original overseer picked by Vault-Tec, and was the only resident aware of the existence of the hidden research sector of Vault 81, which Olivette communicated with through her personal terminal.
During phase III of testing, Olivette had a change of heart, and chose to protect the innocent vault dwellers, in which Olivette disabled the delivery systems, sealing all access to the secret vault, leaving the scientists to die.
Dr. Olivette is only mentioned in Fallout 4.