Seems like very delayed reaction. I don't know if Bella curses Hydra with specific conditions and results in mind (like that poor poor girl with the eating disorder, can I just say 'clinics' that use Imperius for weight loss? *twitch* uggggg) or if she just abuses her while trying to reinforce whatever current 'failing' of Hydra's has her riled up, completely undermining her stated goal of making her a powerful, independent and assertive witch.