This story is an entry in Muffled Chimes' Carbon Leaf Drabbles Contest. The song assigned is "Changeless".
The days between the N.E.W.T.s and summer were maudlin ones for many seventh years. Friends melodramatically pledged to keep in contact, while lovers made plans for the uncertain coming years.
Perhaps the least needed to be said among those who knew they'd see each other more quickly than even they would want. They had thought everything after Hogwarts would be more separated, less meaningful than those fleeting smiles between classes, those long nights in the dormitories. And yet, they knew they would be meeting frequently—but as allies, sisters in arms.
They fought together and they fought alone. They fought with the men they'd chosen to make lives with and with the Order as a whole. They fought their classmates and, three times, they defied Voldemort.
It was sobering to sit down with Dumbledore and hear the truth: their chances were fifty-fifty, each, to bear destiny. Neither spoke aloud, but both wished only for whatever would keep the other safer (and did Dumbledore know?).
Nobody suspected anything untoward when each visited the other before the Fidelius charms obscured them both. They wanted to appreciate the simple things, the way they'd set up their homes, while there was still time. And then there was nothing more than a nagging feeling of loneliness, that someone was farther away than they could hope to travel. All they could do was fight and wait and hope the years would reunite them.
Her husband is there with her. They don't talk much, but they don't need to. They'll always have each other right there.
Sometimes, she sees an old woman. Sometimes, she sees a boy, older and older each time he comes. It must be her son, growing up.
The face from her memory—that brave smile, those loving eyes—never comes to visit. But if she wills herself, she can almost remember making peace with the knowledge that the beautiful schoolgirl would always be just that. She'd never grown old.