It just so happened that James never-in-the-right-place-at-the-right-bloody-time Potter was exactly where Lily wanted him to be. He wasn't in his room, he was meandering around the complex like a lost sort of puppy, avoiding the likes of Salazar Slytherin and reminding himself that he was at least better off than Sirius, who had to sleep next to Severus Snape of all people. James was pretty sure he would rather still be dead than room with Snape, but Sirius was... well, being Sirius about it. James couldn't even say he was handling it well because no he was not.
As he wandered, though, a familiar head of red hair came into view. He paused rounding the corner, squinting to make sure that he wasn't seeing things. Then she spoke, and James had zero questions anymore. That was Lily. Even if he hadn't recognized her voice (which he did) and even if he didn't recognize her hair and body language (he did), he knew that tone anywhere.
He could have played it cool. Honestly, he'd thought about it the whole week without her, but now that she was there in front of him, James had exactly zero chill. "Lily!" he called down the hall. The healer gave him a look, but he ignored it. He got a bit of a running start in her direction and literally swept her up in his arms, spinning her around before setting her down on the ground once again.