There is a series of side quests in Pokemon Legends: Arceus where you must help a man who has a sister who keeps getting lost when she goes out exploring. The Gone Astray requests will take you to various parts of the map where you will need to locate wanda and get her home safely to her brother.
In order to find her, you will need to follow the blue scent that is left from your mount. You will need to use Ursaluna to sniff out the scent in order to make your way to her. If you would rather not waste the time having to find where she is, you can check out the request guides below for all of the Gone Astray quests in Pokemon Legends: Arceus.