Zog and the Flying Doctors by Julia Donaldson (3+)

Zog the dragon, Princess Pearl, and Sir Gadabout have taken to the skies! No sniffly lion or sunburned mermaid will go without care while the flying doctors are on duty. But Princess Pearl's unconventional career path doesn't sit so well with her uncle, the king. He thinks princesses should stay in their towers and embroider cushions all day!When the king's mysterious illness befuddles all the royal doctors, however, it's Princess Pearl to the rescue! She not only heals the king — she also changes his mind about what it means to be a princess.