She was the younger sister of Wolfgang Amadeus Mozart's wife, Constanze, and is remembered primarily for the testimony she left concerning the life and death of her brother-in-law.

When Mozart moved to Vienna in 1781, and lodged for a time with the Weber family, he seems to have flirted with both Sophie and Constanze (the latter of whom he eventually courted and married).

The incomplete Allegro in B flat KV 400, written by Mozart at this time, contains (in W. Dean Sutcliffe]'s words) "a self-contained melodic episode in G minor, with the names of Sophie and Costanze [sic] Weber inscribed above a pair of prolonged sigh figures.

She was married on 7 January 1807 in Djakovar, Slavonia (today called Đakovo, in Croatia) to Jakob Haibel (1762–1826), a tenor singer, actor, and composer; he was the author of a successful Singspiel that was performed many times by the theatrical troupe of Emanuel Schikaneder.

[2] Sophie outlived her younger nephew, Franz Xaver Wolfgang Mozart, by two years and died in Salzburg in 1846 at age 83.