E. Regan was a Human Starfleet officer in the 22nd century.
In 2154, she was named as an Environmental Systems officer on the dedication plaque of the Columbia NX-02. (ENT: "Affliction", dedication plaque).
In January of 2155, she was named as an Operation Support officer on directory placards at the Fleet Operations Center, Sol Sector. His office was in room #3539. (ENT: "Demons", directories)
E. Regan was named after
Enterprise costumer Erin Regan.