Astrid

Astrid is a fortune teller and the single living resident on Isle of Ember in. Astrid's home is easily recognized by the blue decorations above the main entrance.

Biography
When Link first meets her, she is trapped in the basement of her own home. After speaking with her, Astrid asks Link to find her missing assistant Kayo, as only he knows how to open the chamber in which Astrid is trapped. Once he is found, however, all that remains of him is a ghost floating above what could be assumed to be his skeletal remains. Although Ciela initially targets him as a monster, Kayo quickly declares he means no harm and tells Link what he must do to free Astrid. After freeing Astrid, she will ask to tell Link's and Linebeck's fortunes. Through her reading, Link learns he must journey into the Temple of Fire to "defeat the power of darkness" and break the seal imprisoning the Spirit of Power, if he truly wishes to save Tetra from the Ghost Ship.

When Link returns to the fortune-teller's residence after conquering the temple, Astrid informs him that in order to reach the Ghost Ship, he needs three spirits: Power, Wisdom, and Courage.

If Link returns to speak to Astrid throughout the game, she will give him vague hints or clues describing what he must do next in his quest. On a visit directly after obtaining the Regal Necklace from the isle, it is revealed that Kayo and herself are descendants of the Cobble tribe, saying Link was destined to walk on the Isle of Ruins.

Phantom Hourglass manga
As soon as they reach the Isle of Ember, Link and Linebeck decide to stop at Astrid's house. She tells Link about a temple under the island's volcano and instructs him to defeat the monster lurking within. Once Link returns from the temple, she congratulates him and tells him of the three season spirits, captured within several temples across the land. Link and Linebeck depart and follow her advice, soon freeing both Leaf, Neri, and Ceila's memories.

Trivia

 * Although Astrid appears with red hair in-game, her concept art depicts it as silver.