Ilia

Ilia is a young girl who lives in Ordon Village. She is Mayor Bo's daughter. She keeps a close eye on Colin and appears to view it as her duty to keep him out of trouble. She is also extremely close with nature and heals Epona when she is hurt at the beginning of the game. Though she is the daughter of the mayor, she would rather spend time in the wild. Ilia appears to be one of Link's closest friends. It is also somewhat implied that the relationship between Link and Ilia is slightly more romantic than explicitly stated throughout the game.

Biography
Towards the beginning of the game, Ilia is hit with an arrow and kidnapped along with Colin by a group of Bulblins, which leads into Link trying to rescue her. Link eventually locates her in Hyrule Castle Town, but when she sees him, it is apparent that she does not recognize him. Telma reveals that Ilia has lost her memory and cannot even remember her own name. She has been taking care of Prince Ralis, a Zora who she had found collapsed on the road. Telma had taken them in and was helping Ilia care for the Prince. Telma says that Ilia has a lot of courage and that Link should share his courage with her.

Before she arrives in Hyrule Castle Town, she is held captive with Impaz by some Bulblins in the Hidden Village. Impaz helps her to escape and in return Ilia gives her the Horse Whistle, a whistle in the shape of Horse Grass that can be used to summon Epona. Ilia was apparently locked in her room at the beginning of the game making this item for Link but never got the chance to give it to him.

Renado looks after her in Kakariko Village, before Link restores her memory and she stays there for a while afterwards. After her memory is restored, she gives Link the Horse Call (which is the item that jogs her memory), saying that she made it for him and was going to give it to him before he left.

During Lanayru's narrative of the Fused Shadows, Ilia, along with Link, depict Hyruleans as they watch the creation of Hyrule and the Triforce. Afterwards, she appears blank-eyed (representing the people blinded by the Triforce's power) and attempts to kill Link with a knife. She is presumably killed by Link in the narrative.

During the game's ending, Ilia and the rest of the Ordon children are seen returning to their home inside a carriage. She is last seen witnessing Link's departure from the village.

Super Smash Bros. Brawl
Ilia appears as a randomly-collected trophy in.

Hyrule Warriors
Ilia appears in as a costume for Zelda in the  DLC pack.

Trivia

 * Ilia seems to be based on the character Saria from because both are very close to nature, and are childhood friends with Link. In Japanese, the letters "r" and "l" are the same so that would make Ilia "Iria" and Saria, or "Salia" and Ilia.
 * In concept art, Ilia was drawn with the pointed ears of a Hylian.