Emeralda Kasim

Emeralda was created by Kim Kasim during the Zeboim era, four thousand years before the beginning of Xenogears. She is a nanomachine colony created to resemble both Kim and Elly, probably in an attempt to make her their 'real' child, although she never had the chance to awaken and fulfill that role. She was also Kim's attempt to create a perfect human being in a time when humanity was steadily destroying itself with radiation poisoning and all-out war a wish come true for Kim and Elly, who could not have children because of those circumstances.

(Source: Guardian Angels)