The first time she was confused and struggled to remember a memory about her past, she worried that Antonin was somehow messing with her memories. Maybe he was cursing her when she was asleep or drugging her food. How else could she explain the periods of time that passed when she could hardly remember her own name? Part of his orders when she was first sent to his house was to reprogram her into a dutiful, little puppet for the Dark Lord. Most of that involved a great deal of propaganda and debates that he inevitably won. No curses were needed. No spells were even used. He simply had very convincing points to make. It wasn't necessary for him to access her thoughts and memories at all.