She likes you, Marvolo. But before you asked her to the Ball, she had started dating Cedric Diggory. And she really, really fancies him. And he really fancies her, too, I think.
So when you asked her, she didn't know that you wouldn't be offended if she said no.
It's not your fault. And she knows that, too. But that's why she's been not as excited about the ball as she ought to be.
Re: Private Message to Padma
She likes you, Marvolo. But before you asked her to the Ball, she had started dating Cedric Diggory. And she really, really fancies him. And he really fancies her, too, I think.
So when you asked her, she didn't know that you wouldn't be offended if she said no.
It's not your fault. And she knows that, too. But that's why she's been not as excited about the ball as she ought to be.