What does Bella's a shield mean?

Answer 1

no one can use powers on her involving the mind (its a shield of the mind) its also why eddy cant read her mind and Jane cant do that stingy stuffz

Answer 2

In the Twilight series, Bella Swan is described as a shield because she has a rare ability to project a mental shield that protects herself and those around her from psychic powers that try to influence or harm them. This ability plays a crucial role in the story as she learns to control and use it to protect her loved ones.