Candy Quests are a competition against Candy. In addition to the reward for completing the quest, there is a separate quest to beat her 6 times in a row. If you fail to complete the weekly quest one week, this will be reset to 6. The reward for completing this is the table from the Candyland decor set.
Candy's WorkshopEditCandy is treated the same as any of your other friends on Sword Quest. This means that you can visit her workshop (receiving a spin of the Friend Wheel the first time you do so) and hammer her swords. This is recommended as you gain xp, CP and mastery in the material when you do so. Candy will only begin crafting swords when you enter the workshop. The decor in her workshop is the Candyland theme.
Candy also sets you a quest in which she offers you a reward for hammering her swords for her. You must hammer her swords 100 times. Using the fire or ice hammer does not count towards this. The reward for completing this quest is 10,000 coins, 5,000 xp and the bookshelf from the Candyland decor set (usually costing 20 smith tokens).