Yueyue is an Espurr Spirit Medium (She also happens to be, a Small Medium at Large). In Pathfinder there is a Psychic class, but none of their features relate to be a classic psychic medium who talks to ghosts, so I am just going to do my own thing and nobody can stop me! Mainly I had the idea of basing this character on the Fey family from Phoenix Wright Ace Attorney. The Women of the Fey family specifically have a very strong spiritual power, this mainly allows them to channel spirits of the dead into their body and then physically transform into that person for a period of time, but also their spiritual powers can be used to charge Magatama gemstones so the wielder can see if someone is withholding secret.

Yueyue was raised in a small isolated village where the kingdom trains up a unique caste of soothsayers and mediums who are meant to specifically server in the royal court at the behest of their king. This village is heavily guarded to protect the Mediums like a valuable resource but also to keep them contained and under control. The kingdom would not want their mediums being kidnapped and used by another kingdom, or influenced to side against their king, and should a medium decide to use their powers against the king, the guards who protect them could turn into their executioners.

Yueyue does not understand any of this yet, she is young, very innocent, and uninformed so when she managed to get out of the village without the guards noticing her to play, it is treated as an incident of national security!