During this period, she kept a private journal which provides a unique picture of Mahler's personal, professional and creative life during and just after his thirties, including an exclusive preview of the structure, form, and content of his third symphony.
Bauer-Lechner was the eldest child of five children (four girls and a boy) born to the Viennese bookshop owner and publisher Rudolf Lechner (1822–1895) and his wife Julie, née von Winiwarter (1831–1905).
However, from various press notices in the Viennese dailies it was clearly her sister Ellen (or Helene) who frequently appeared on such occasions, and also in chamber music concerts with director Joseph Hellmesberger Sr.
Alexander Bauer (1836–1921), whose first wife (Emilie, born Russell) had died from pneumonia on 22 March 1874, only one day after she had given birth to her third daughter (cf.
It has therefore been speculated by Danish Mahler-scholar, Knud Martner, that the last-born daughter, christened in a Protestant church (though both parents were Catholics), on 7 April 1874 and named Minnie Emilie Forster Bauer (she died on 31 July 1956), was in fact the illegitimate child of young Natalie.
In her later years, Bauer-Lechner became an outspoken feminist, and in 1918 she allegedly published an article on the war and the need for female suffrage, which led to her arrest and imprisonment.
Recently owned by the late Mahler-scholar Henry-Louis de La Grange, the Mahleriana manuscript is not intact: numerous pages have been torn out by unknown hands, and there is no indication of what they might have contained.
During her life, Natalie Bauer-Lechner was in the habit of lending her manuscript to friends and acquaintances (E.H. Gombrich reports that his parents had it in their possession for some time), and it is presumably this practice that allowed material to be removed.