O'Connel was a member of the Starnes Exploration Party in 2268. She committed suicide by taking a lethal cyalodin. Her corpse was found and examined by James Kirk, Spock and Leonard McCoy, who discovered a vial of the poison in her mouth. (TOS: "And the Children Shall Lead")
She was played by an unknown actress.
Her costume was previously worn by Janet Wallace in "The Deadly Years".