Magnus employs us to rescue Bluebelle from her crystal prison next. In fact he will give us 2 crown for rescuing her.
You must be at least at level 21 in order to expand to Bluebelle's area of the kingdom.
Bluebelle immediately starts giving quests, her first one being Got Magic. You can get 5 fairy vials from her home in the Fairy Realm (24 gold, 4 min).