Help her up, let her know

As you apologize, helping the girl up to her feet, you whisper that her top has become a bit loose. Shocked, she looks down and realizes that you're indeed right, and immediately she adjusts her top to its rightful place. She thanks you, blushing a bit and turning away. She grabs her books and walks away slowly, giving you one small smile as she looks back. You're not sure what to think of that, but don't have time to ponder as the bell rings it's time for class.