"like the Lady of Branxholm Hall "

The Lady of Branxholme was a real historical figure who was portrayed by Sir Walter Scott as the wizard Lady of Branxholm (or Branksome) in his narrative poem 'Lay of the Last Minstrel'. Here, Jane Austen is quoting for the second time from Scott's poem (see bookmark p.80), on this occasion, from Canto 1, stanza 20.