Rosetta had seen men who would constantly be on her tail, trying to pursuit her. Draco wasn't the first man to behave in that manner. However, he was the first who she was unable to shake off. He stuck till the end until she began to get terrified when he mentioned giving up on her.
She never expected him to court her during a duel. Rosetta didn't think much and pushed it off, rejecting his proposal. However, it wasn't the end of his pursuit. Draco was nothing but someone she thought was a passerby, but it would stick to her head till the end.
Her heart was moved every time she was with her. She was motivated to leave with him this instant when he would court her. However, her feet refused to move. Her heart and mind were in turmoil.