Arielle was Lirael's mother. As one of the Clayr, she Saw that she must bear the child of Terciel. She left the glacier while her daughter was five years old and died in an unknown location. Lirael learned of Arielle's death when she was ten. The circumstances are the subject of rumors. One states that Arielle became the court seer of one of the barbarian warlords in the lands to the north (a position considered undignified by the Clayr) and was killed by a political rival.
In Goldenhand, it is revealed that Arielle died of a wasting sickness when Lirael was ten years old. Shortly beforehand she had a vision of Chlorr of the Mask and the northerners invading the Old Kingdom during Lirael's tenure as Abhorsen-in-Waiting, and spoke to the older Lirael from the past to warn her and instruct her on how to defeat Chlorr.