Definition of "in the flesh"

[S]he [Edwina, mother of Tennessee Williams] was indeed Amanda [Wingfield, character in Williams' play The Glass Menagerie] in the flesh: a doughty chatterbox from Ohio who adopted the manner of a Southern belle and eschewed both drink and sex to the greatest extent possible.

2014 November 14, Blake Bailey, “'Tennessee Williams,' by John Lahr ”, in The New York Times‎