Julie Matthews (Francesca Reale) is the teenage daughter of Tabitha and Jim, and the only confirmed Storywalker in Fromville. She discovered the ability accidentally in S2E1 when she threw a rope down to Boyd from a different point in time. The storeroom beneath the town acts as her library: each object on its shelves is a bookmark into a specific moment. Julie has used this ability to witness the massacre Victor survived, to confirm MIY feeding on remains, and to map the town's historical timeline in ways no other character can access. S4 has positioned her as an active investigator rather than a reactive victim.
The community consensus is that the storywalking ability chose Julie for a reason the show hasn't disclosed. Leading reads: she has some innate resonance with the town's time-structure, possibly tied to the reincarnation cycle. The S4E6 Randall conversation. where he tells her Township concepts leak into the real world as stories that could become escape tools if reverse-engineered. has shifted Julie from witness to potential architect of the exit.