Cassandra Fraiser

Cassandra is the sole survivor of a planet that had been wiped out by a bacterial plague. She was approximately eleven or twelve years old at the time, placing her birth in 1985 according to Earth's dating system.

Biography
SG-1 brought her back to Earth, partly out of sympathy and partly because they believed they were indirectly responsible at the time. However, they discovered the Goa'uld, Nirrti, had planted a time bomb inside Cassandra in an effort to destroy Earth's Stargate.

Samantha Carter bonded with her and was more than a little reluctant to leave her at the bottom of an abandoned nuclear facility, so the bomb would go off without killing anyone except her. However, it occurred to Carter that Cassandra's condition had deteriorated when she was brought near the Stargate and she had returned to her normal condition when taken far enough away from it. Therefore, she correctly concluded, the bomb inside Cassandra would only go off if she was in close proximity to the Stargate.

The bomb inside Cassandra was absorbed back into her system, so, presumably she can now be near the Stargate without any danger. However, the Naquadah in her blood allows her to identify Goa'ulds. Janet Fraiser adopted her and Carter continued to pursue her relationship with the young girl.

On her birthday, when she was about fifteen of sixteen, Cassandra experienced a new affliction and SG-1 returned to Hanka, where they discovered Nirrti had been experimenting with the Hankan children in an effort to create a genetically-superior host. When they captured Nirrti, the SGC agreed to trade Nirrti's freedom for Cassandra's life. Nirrti revealed she was planning to begin her experiments anew.

After Fraiser died, in 2005, Carter looked after Cassandra more, because she went through a hard time after the loss of her adopted mother.

When SG-1 was attempting to return to the present from the year 1969, they accidentally found themselves far in the future. Cassandra, now an old woman, addressed them, explaining how Carter had told her what would happen when she was "old enough to understand," and sending them back to 1999 through the Stargate, telling them that their journey had only just begun.