Grace was sure that telling her doubts about Alex will only make Serena go against her. Without solid proof, it's not possible because Serena is in his control without a way to break free.
Grace wrestled with her doubts about Alex, her mind spinning with the potential consequences of revealing her suspicions to Serena. She knew that without solid proof, it would be futile to try and convince Serena to see Alex for who he truly was. After all, Serena was under Alex's control, unable to break free from his influence without a way to resist his manipulations.
With a heavy heart, Grace realized that telling Serena about her doubts could only serve to push her further into Alex's grasp, driving a wedge between them and potentially endangering Serena even more. Despite her concerns, Grace knew that she needed to tread carefully, biding her time until she could find concrete evidence to expose Alex's true nature.
