Hermione only knew what she'd seen with her own eyes that one time. It wasn't as if she made a habit of keeping up with who was snogging whom. Therefore, she left Ginny with only what she had said earlier on the subject.
Ginny's explanation fit Hermione's sudden feelings perfectly. She lightly nodded her head as the other girl spoke about how it had just seemed to fall naturally into place. When Ginny asked Hermione point blank if she wanted to kiss she didn't know how to answer.
"Um, I don't know," she moved her hand off Ginny's knee and ran it through her own hair. She didn't want to force Ginny into anything. "Do you?"