Finding the missing sister is one of the Gratitude Crystals side quests you can complete in The Legend of Zelda: Skyward Sword.
Completing this side quest will reward you with both five Gratitude Crystals and a very useful empty bottle, which you can use to carry a variety of potions and other items.
Below you'll discover where to find the missing sister in Skyward Sword, so you can add another bottle to your collection.
If you'd like to learn more, visit our Skyward Sword walkthrough.
How to start and complete the Missing Sister side quest in Zelda: Skyward Sword
To start the Missing Sister side quest in Skyward Sword, you need to talk to Parrow. He can be found either walking around Skyloft plaza during the day or in his house, which is south of the Knight's Academy, at night.
Parrow is worried about his sister, Orielle, who hasn't returned from her regular flight yet and will ask you to look for her. After agreeing to this task, head out into the sky and fly towards the Lanayru Desert entrance.
On the right-hand of the yellow light pillar, you'll discover a small platform floating on the sky and, atop it, Orielle.
Land on this island and talk to Orielle who will explain that her bird is injured, before asking you to return to Parrow for some medicine.
This means it's time to fly back to Skyloft and talk to Parrow again. He'll give you a bottle of Mushroom Spores for Orielle's bird and, best of all, you get to keep the empty bottle. Hurray!
It's important to note that, if your Adventure Pouch is full, Parrow won't be able to give you the empty bottle. Instead, you'll need to deposit an item at the Item Check to create space in your Adventure Pouch.
With the Mushroom Spores in hand, return to Orielle and, after giving her the spores, you'll receive five Gratitude Crystals.
Our Skyward Sword walkthrough will help you find every Heart Piece and Empty Bottle. We can also help you defeat Ghirahim, Scaldera, Moldarach, The Imprisoned, Koloktos, Tentalus, Bilocyte and Demise. You can also discover where to find Kukiel to unlock the Gratitude Crystals and a number of side quests, including the toilet paper quest, missing sister location and party wheel location.