I can't remember, but if you bring up your map and click on 'show active quests, the map will show you where to go. The appropriate square will glow yellow. You can also click on the quest on the left hand side and re-read it.

Try the store in the Haunted Village Store, yes there is a store in there. The item might be available from there. Or perhaps you have to get farther into the Haunted Forest before you can get that item, it might be from one of the possible multiple Rosa quests.