Ruby Cooper, 52, is said to have bombarded the banking boss with calls and sent abusive messages in breach of the restraining order imposed on her in October last year.
She had been found unanimously guilty of breaching her restraining order imposed on her after she sent various abusive messages to Mr Hester in 2012.
The order banned her from contacting any director or former director of RBS but she was arrested again after NatWest employee Fiona Macdonald flagged up her latest calls to police.
At Snaresbrook Crown Court, in London, Judge Martin Zeidman remanded Cooper in custody until April 3.
Cooper, of Barnet, north London, will be charged with two breaches of a restraining order.