Books in the DragonChild series in order

The sixth DragonChild adventure. Tia is on a quest to retrieve the DragonQueen's six stolen Jewels of Power from the High Witches. She has all the jewels but the healing pearl - which is held by the last High Witch, her mother, Ondine. Ondine has no idea that Tia is her daughter. She's determined not to lose the pearl to a thief who has brought down her five sisters. But Tia is equally determined to finish her quest, without her evil mother learning the truth...