It wasn't that hard to get the time-turner. After the battle everyone had been so exhausted that it didn't seem strange for someone to ask to see the item. In retrospect Hermione should have known better than to have let George take it, but in times of tragedy you never really do think straight, do you?
Now he stood alone, time-turner between trembling fingers and a purpose. A solid, life-changing, purpose. If they all expected him to just give up, to grieve and mourn for Fred, then they were wrong. A twin without a twin, isn't one at all. They're normal, and George Weasley did not do normal.
