Night gathers, and now my watch begins. It shall not end until my death. I shall take no husband and bear no children. I shall wear no gowns and no jewels. I shall live and die at my post. I am the sword in the darkness. I am the watcher on the walls. I am the shield that guards the realms of men. I pledge my life's blood to the Night's Watch, for this night and all the nights to come. -The Sisterhood of the Night's Watch

There must always be a Stark in Winterfell, or: Sansa goes home.

Somewhere far away, far from the home she once knew – the home she can no longer remember, or she can but she does not wish too – there is a girl who does not remember her name, nor anything of the life she came from. Until the night she dreams of wolves.

Val didn't save Jon Snow - that was his direwolf and the red woman - but she did steal him.

When Dorne became one of the Seven Kingdoms, they agreed to replace the Westeros Law of Inheritance with the Dornish Law, so that the same laws would be followed throughout the realm. Or, Five times there was no male primogeniture in Westeros, and this wasn't as helpful as you might expect.

"You could always stay." "And what should I do at the Wall, Sam, style myself as the Night's Queen? Or Lady Commander of the Night's Watch?" "Well, we do let girls in nowadays."

Lyanna Mormont keeps the ravens.

Lyanna Stark thwarts a kidnapping, and receives an interesting offer.

King's Landing swallows Dornish princesses and chokes on their bones.

If you want a happy ending, that depends, of course, on where you stop your story.