She wakes up tired.
Everyday, Ginny Weasley'll get out of her four-poster, no matter how tired she is. She learned early on in the year that going back to sleep will only make her more exhausted and earn her another detention from the Carrows.
He was long gone and she knew that no matter how tired she was, he was far worse.
She could have saved him. Harry could be with her at Hogwarts right then. Well, maybe not. He was the most wanted person in Britian. They could have been together, though. She could have went with him, where ever it is that her brother, ex-boyfriend, and best female friend went off to.
With one tear, one desperate plead, she could have shattered the entire wizarding world by begging him to stay. Even the Chosen One wouldn't have been able to resist. Especially the Chosen One, actually. One broken whisper of 'Let's hide away together' and Harry would have been sold, she was sure of it.
That couldn't happen, though. Whatever they were doing, Ginny was sure they were ridding Voldemort of his power and making the world a better place. Slowly. Agonizingly slowly.
So, like the brave Gryffindor she is, Ginny Weasley continues to give hope to Hogwarts by restarting Dumbledore's Army with Neville.
But she goes to bed tired.