Sometime prior to her Starfleet career, she worked for a auto-insurance company, a period of her life that she would fondly recall during dangerous Starfleet missions.
In 2265, Starfleet Command assigned her a mission to the planet Delta Vega, to investigate the loss of communications with the Starfleet outpost on the planet. Upon beaming down to the planet she found the area infested by two native species, the polarilla and snow slug. She fought her way past members of the animal species on the surface of the planet until she fell through the ice into a cave network. There she encountered more of the animals, including a particularly large polarrila which attempted to use it's bulk to create concussive force waves to push her back. Fortunately Esurance's phaser was sufficient to disable the animal and allow her to continue. Esurance finally found her way into the base only to find it had also been infested by the animals, after fighting her way through she found a damaged area of the base and located Keenser, another Starfleet officer. However at this moment an especially large snow slug burst through the base's wall, lashing out at Esurance with its tentacles. Once again her phaser proved to be sufficient deterrent, and once she had neutralised the threat she completed her rescue of Keenser. (TOS video game: Delta Vega: Meltdown on the Ice Planet)
The game Delta Vega: Meltdown on the Ice Planet is primarily a promotional device for the Esurance car insurance company and the 2009 Star Trek movie. The character Erin Esurance originated from Esurance's general advertising campaigns, in which she ordinarily plays the role of a spy cum insurance sales person.