This is the definition that I am familiar with
A term of endearment for an energetic, bouncy person.
A spastic, white dancer.
Also refers to someone that is messy and chaotic, in a cute way.
Sally's excited jumping is adorable, she's such a whirling dervish!
My house was clean before that whirling dervish spent the night!
This is the definition that I think the book is referring to.
A member of a Muslim (specifically Sufi) religious order who has taken vows of poverty and austerity. Dervishes first appeared in the 12th century; they were noted for their wild or ecstatic rituals and were known as dancing, whirling, or howling dervishes according to the practice of their order.
Some interesting sites.