She and Pierre were trying to determine whether Sudowoodo is a Rock-type or a Grass-type. She argued that knowledge written in books is not always right. She and Pierre were doing observation on a wild Sudowoodo. They saw it using the move Razor Leaf and Vine Whip, which is impossible for any Rock-type Pokémon to learn, therefore she concluded that Sudowoodo is a Grass-type Pokémon. Eventually they learned that Sudowoodo is in fact a Rock-type, due to the fact that the wild one they studies was afraid of water, which is abnormal for a Grass-type Pokémon. With the use of the move Mimic, Sudowoodo was able to imitate moves not of its type.
Marie was shown to have a grandfather, who is a Fisherman. This man was inspired by Marie's hope in finding a Sudowoodo and was willing to offer anyone a trip to the other side of a river with his boat, to those who managed to catch one and show it to him.