She is a self-proclaimed "Adventure Maniac" who wants to get autographs of great adventurers.
She first meets Lulua after saving her from a monster attack. She wanders from town to town through the year. When she later requests an item from Lulua she reveals she doesn't like to fight monsters and instead uses traps to catch them. It is revealed she has an autograph book with the signatures of various adventurers and is obsessed with them.
In Arls she attends an event held by Meruru to show the various types of mushrooms in the region. Jeltje quickly bites into a poison mushroom before Meruru identifies it, losing consciousness.
Since Jeltje is wandering the Arland Republic, she will occasionally be found in a gathering area. During these encounters she operates a shop that sells items from the area.