«The Royal Search for Shenanigans» by Nita Marie Clark

Princess Lillian, an adventurous modern-day princess, faces many changes when her father becomes king.
An ancient spell cast centuries before by a set of grand wizards has left Princess Lillian with a riddle and destiny of monumental proportions.
As a young Princess, her life was always planned by others. However, now she must embark on a journey where all of her choices and their consequences will be her responsibility. The outcome of her decisions could make her life even more complicated.
In love with her new quarters, beautiful rooms filled with beautiful antique furniture and lovely murals decorating the walls. A strange, and mysterious past surround her quarters, which have been locked for almost one hundred years did not bother Lillian at all. It was like living in a fairy tale.
The princess discovers a white leather satchel filled with intriguing information about dragons, an isolated kingdom, and pages of an old diary written by one of her ancestors hidden behind one of the drawers in the antique vanity. Lillian understands why her Great-Great Grandmother Flora had ordered the doors locked. And how the gorgeous antique music box, containing a lovely heart-shaped locket she inherited hides significant clues to the riddle's answer.
Trying to figure out the riddle by herself, she discovers the ancient land of shenanigans and a hiccuping dragon. Upon returning home she accidentally sets loose a mischievous dragon in the Land Of Zen!
In need of help, she turns to her two best friends, her royal cousins, and an old set of Princess Rules, to try to put all the pieces of the riddle together and fulfill her destiny to free the Land Of Shenanigans. Can she do it all before the land of Shenanigans and it's dragons are doomed to live in total isolation FOREVER?