Hedril

From Memory Alpha, the free Star Trek reference.

Hedril was a Cairn child, the daughter of Maques. In 2370, Hedril and Maques visited the USS Enterprise-D as part of a diplomatic mission. The Cairn were a telepathic species that had no concept of spoken language. She met Lwaxana Troi when Lwaxana served as an interpreter between the Cairn and the Federation. She reminded Lwaxana Troi of her deceased daughter, Kestra, triggering the release of painful memories that Lwaxana had suppressed for years. This caused Lwaxana to lapse into a coma. Deanna Troi met with Hedril, who said that she knew she made Lwaxana sad. When Troi entered into her mother's mind, she found Hedril in her subconsciousness. Troi encountered Hedril a second time and discovered that she represented her sister Kestra who died in an accident for which Lwaxana blamed herself. (TNG: "Dark Page")

Hedril was played by Kirsten Dunst, who appeared in metaconscious sequences playing the role of Kestra without Cairn makeup.