She's convinced herself that they're the exception. This war was not going to tear them apart. He was still James, and she was still Lily, and that was all that mattered.
He was still tall, still scrawny. His hair still poked up at angles that defied the laws of physics and he still wore the watch his father gave him before his death. She was still short, still petite. She still loved Sugar Quills and clean socks and she still wore her mother's locket at all times around her neck.
They're the exception, still the same as they'd always been. He still hums when he does the dishes with neither tone nor tune. She still sneaks up behind him to press her forehead into his shirt and feel him breathe before he'd turn around, laughing because he loved to tease her about her back fetish ("Don't flatter yourself," she'd scoff. "It's the fabric I love").
The world was burning all around them, but she told herself that they'd outlast the storm.
Only, James didn't used to drink. Not at this rate. His laughter no longer fills the room like it used to and he sports far too many wrinkles for a nineteen year old boy. And she didn't used to need an elixir to get through the day and she's never had nightmares like these, but she's convinced herself that these are only details.
The collection of obituaries above their mantel place grows by the day, and those are only the people whose deaths have been confirmed. Slowly, she realizes those are the easiest to put up.
He pins up a tattered picture of his maiden aunt, a gesture she knows means that he's accepted her as dead even if the Prophet hasn't. She cries when she pins up the one photo they have of Benjy Fenwick.
They still fight for the Order, just as they always have and always will. She's wise enough to realize that a battle cry is still a cry, but fighting means they're alive and that's all she needs.
She's convinced herself that they are the exception, but she knows she is wrong. This is war and there is no escaping without any damage or scars. But he was still James and she was still Lily and the war could not change that they were still together and they were still alive.
What does change is her last name, because this is war and they will live before they die. They will take their fate into their own hands because Lily's never liked Divination and James has always been a bit of a rebel. They will live and laugh and love because they are the exception.