Elizabeth
Elizabeth was the binary clone of Commander T'Pol and Commander Charles Tucker III of the Starfleet vessel Enterprise. She was created without their knowledge or consent, their DNA illegally obtained by Terra Prime. (ENT: "Demons", "Terra Prime") She was named after Commander Tucker's younger sister, Elizabeth Tucker, who was killed in the March 2153 Xindi attack on Earth. (ENT: "The Expanse", "The Xindi")
Elizabeth's existence was discovered in January of 2155 when a former Terra Prime member, Susan Khouri, gave her life to deliver a strand of Elizabeth's hair to T'Pol. At the time of the discovery, Elizabeth was no more than six months old, suggested she had been created during the latter part of 2154. (ENT: "Demons")
Being a Human-Vulcan hybrid, Elizabeth was used by Terra Prime leader John Frederick Paxton as an example of what he believed could happen if Humans and non-Humans were to join together in an interstellar alliance. Paxton believed that such cooperation would lead to the Human genome becoming so diluted that the race itself would become practically extinct. With Elizabeth as "proof", Paxton demanded that all non-Humans vacate the Sol system within 24 hours or else he would destroy that which he saw responsible for upcoming Coalition of Planets – Starfleet Command.
Ultimately, Paxton's plot was foiled by Captain Jonathan Archer and the crew of Enterprise and Elizabeth was united with her parents. Sadly, Elizabeth died soon afterwards, on 22 January, due to a fever and an elevated white blood cell count. Elizabeth's importance as the first known cross-breed offspring of a Human and an alien species was such that, following her death, the delegates from the conference for the Coalition of Planets wished to attend the child's funeral services.
Although it was initially believed that the infant died due to the incompatability of Human and Vulcan genes, Doctor Phlox later discovered that Elizabeth had died due to a flaw in the cloning procedure used to create her. Furthermore, Phlox determined that there was no medical reason why Human and Vulcan DNA could not combine to produce a child in the future. (ENT: "Terra Prime")
- Baby Elizabeth was "played" by two infants (twins) named Grace and Riley. It has been speculated that Elizabeth's death was one of the reasons why T'Pol and Tucker ended their relationship soon after, as revealed in "These Are the Voyages..." (ENT).''