[2][3][4] Through her brother Jacques de la Ferrière, then chief of protocol at the Élysée Palace, she met President François Mitterrand in November 1984.

She recounts this experience with people at the end of their lives in a book with a preface by Mitterrand, La mort intime,[7][8] published by Robert Laffont (1995) and translated into some twenty languages.

[4] From 1996 to 2002, she attended conference where she passed on the experience of accompaniment acquired with people at the end of life,[12][13][14] and training courses for health professionals.

In 2002, Jean-François Mattei, Minister of Health, the Family and the Handicapped, entrusted Hennezel to research and report on the end of life.

[18] Hennezel runs seminars on "the art of aging well" for [udiens,[19] the mutual insurance company and pension fund for the entertainment, audio-visual and press professions.