Once Upon a Time, River told the Doctor that we are all just Fairy Tales. Really, though, isn't it the other way 'round?
River Song loved Fairy Tales. She always had, for as long as she could remember. Further back than that, really.
The stories existed before all her other memories even began. They had been her closest childhood friends. Far too often, they'd actually been her only ones. They'd kept her going through even the coldest and loneliest nights of her life, nights when she hadn't been sure she'd live to see the sunrise. Even through the one night when, finally, she hadn't. She might simply have curled up in some forgotten corner and let sleep sweep her into oblivion. Become just one more piece of flotsam and jetsam washed up against the shores of the Universe.
But instead, the Fairy Tales had been there, whispering in her ears, filling her mind with images and feelings so strange and exciting she could barely understand them. Yet, somehow, she did. Somehow they kept her going, kept her living, even when nothing else could.
She had her favorites, of course. Snow White she was especially fond of. The story of the beautiful young girl escaping the Evil Witch and going to live in the forest with a group of strange old dwarfs had always appealed to her. Only she always preferred the versions that had more dwarfs, without those silly names. She preferred to name them herself. Grumpy and Dopey she often kept, but the others usually ended up with names like Dandy or Toothy or – and this one had always been one of her favorites – Pretty.
She'd spent countless hours playing with her dwarfs, imagining them each in her head. In the end, though, the Evil Witch always found Snow White again and the dwarfs proved powerless to protect her. Instead, it was the handsome young Prince, riding in on his white horse at the last minute, who saved the day.
One of her other favorites – like that of thousands of other little girls, though she hadn't of course known that then – was Cinderella. When her Evil Stepmother tried to force Cinderella to stay at home and work for her, Cinderella's Fairy Godmother had magically appeared out-of-nowhere to rescue her. She'd then helped Cinderella get ready for the grandest party ever where the most handsome Prince in the world fell in love with her at first sight. He married her (of course) and she never had to go back to live stuck in that old house with her Evil Stepmother ordering her about again. Not ever.
River's favorite Fairy Tale of them all, though, had always been Sleeping Beauty. The story of a kind King and his Queen living in their beautiful Kingdom, who rejoiced in the birth of their perfect little baby girl. But then, much to everyone's horror, the little Princess fell under an Evil Curse. One day, she was destined to prick her finger on a spinning wheel and then she, and her parents, and everyone else in their entire Kingdom would fall into a deep, deep, deep forever sleep.
All was not lost, though, because the little girl's Fairy Godmother had a plan. She took the child away and hid her deep in the Forest where there was neither magic nor spinning wheels and so the Evil Curse would never be able to reach her there.
Only, when she grew up, the little Princess (who didn't know she was really a Princess but thought she was just a little girl running about in the Forest) got bored. She snuck out of the Forest and went off to go see the Big City and the Castle of the King and Queen. As soon as she got there, though, she fell back under the Spell of the Evil Curse. It led her to a spinning wheel and made her prick her finger upon its needle. Sleeping Beauty fell instantly fast asleep, and so did her parents and everyone else. Silence reigned supreme throughout the once fair Kingdom.
Luckily for Sleeping Beauty (and everyone else, but only the Princess really matters in this kind of a story), a handsome Prince who had first seen her back when she'd been a tiny little baby and then more-or-less accidentally only a few times since then but who was already pretty much totally in love with her anyway, bravely fought his way into the Castle. He broke the Evil Curse, waking the Princess (and everybody else) and thus restoring Peace and Harmony throughout the Kingdom.
That one was definitely her favorite.
Though of course it didn't hurt that, over the years, the Fairy Godmother in all her stories had somehow become one slightly-mad-but-still Very Good Wizard.
And so had the Prince.