The Light Princess has humor written all over it, though, at the same time, it is a deeply profound story.

Some of the humor jumps off the page from the very first lines where George MacDonald (GMD) describes how the king is cross with the queen for not providing him with a child the way the other queens did for the other kings.  GMD writes:

Once upon a time, so long ago that I have quite forgotten the date, there lived a king and queen who had no children. And the king said to himself, "All the queens of my acquaintance have children, some three, some seven, and some as many as twelve; and my queen has not one. I feel ill-used." So he made up his mind to be cross with his wife about it. But she bore it all like a good patient queen as she was. Then the king grew very cross indeed. But the queen pretended to take it all as a joke, and a very good one too. "Why don't you have any daughters, at least?" said he. "I don't say sons; that might be too much to expect." "I am sure, dear king, I am very sorry," said the queen. "So you ought to be," retorted the king; "you are not going to make a virtue of that, surely." But he was not an ill-tempered king, and in any matter of less moment would have let the queen have her own way with all his heart. This, however, was an affair of state. The queen smiled. "You must have patience with a lady, you know, dear king," said she. She was, indeed, a very nice queen, and heartily sorry that she could not oblige the king immediately.

Chapter 2. Won't I, Just?
The king tried to have patience, but he succeeded very badly. It was more than he deserved, therefore, when, at last, the queen gave him a daughter--as lovely a little princess as ever cried...

The story goes on, and, as in Sleeping Beauty, the princess is cursed by one who was offended at being passed over with an invitation to the celebration of her birth.  In this story it's her Aunt Princess Makemnoit, (Make them know it,) who...

"...muttered the following words, loud enough for those beside her to hear:-- "Light of spirit, by my charms, Light of body, every part, Never weary human arms-- Only crush thy parents' heart!" They all thought she had lost her wits, and was repeating some foolish nursery rhyme; but a shudder went through the whole of them notwithstanding. The baby, on the contrary, began to laugh and crow; while the nurse gave a start and a smothered cry, for she thought she was struck with paralysis: she could not feel the baby in her arms. But she clasped it tight and said nothing. The mischief was done. 3. She Can't Be Ours. Her atrocious aunt had deprived the child of all her gravity." 

While it's funny enough to think of a child that might float away on a breath of wind, it's even funnier that she has not a care in the world about her condition, and so, the "lack of gravity," is a pun, in that the princess is not only weightless, but also care-less. (This concept of a lack of weightiness, might remind some of the Bush-Gore political campaign when Bush was accused of lacking "gravitas".)    :)

The story ends with the princess breaking the curse when she finally begins to care for someone and gives of herself to free a loving prince from certain drowning.  The princess and her old nurse attend to the prince until finally he opened his eyes.

[The princess] lay on the floor and wept, and this rain within doors was far more wonderful than the rain out of doors. For when it abated a little, and she proceeded to rise, she found, to her astonishment, that she could not. At length, after many efforts, she succeeded in getting upon her feet. But she tumbled down again directly. Hearing her fall, her old nurse uttered a yell of delight, and ran to her, screaming,-- "My darling child! she's found her gravity!"

This is the best kind of humor, in that it helps us to see something true about ourselves and brings to our hearts an important lesson; that we ought to care for one another, and not be care-less.

The story concludes, happily, of course:

So the prince and princess lived and were happy; and had crowns of gold, and clothes of cloth, and shoes of leather, and children of boys and girls, not one of whom was ever known, on the most critical occasion, to lose the smallest atom of his or her due proportion of gravity.

John Kermott