|Out of universe information|
She had once lived on a world with both her parents. One day, a runner named Kiryk stayed in her village for only one night. However, the Wraith traced his signal and culled her home. Her entire civilization was wiped out. Somehow, Kiryk was able to save her and brought her along in his travels. He grew into a father figure for her, by protecting her from the Wraith, and even hand-made a doll for her. However, she once had an accident, where one of her legs was seriously wounded. Soon, her wound became infected, which caused her health to deteriorate.
They came to M33-985, where Kiryk kidnapped Dr. Jennifer Keller to help Celise. He didn't simply ask because he wouldn't risk being declined. Keller was able to clean the wound the best she could, but the infection was still severe. She planned to take her to Atlantis to save her life, and after Kiryk's tracker was disabled, he would live free enough to look after her properly. However, Kiryk went through the Stargate to lure the remaining Wraith on the planet after him. Celise was taken to the Atlantis infirmary briefly before Erran on M33-985 adopted her to look after her. (SGA: "Tracker")