Wikipedia Biographical Summary:

"...Maria Sophie Weber (1763?[1] – 1846) was a singer of the 18th and 19th centuries. 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..."

"...She was born into a musical family, the youngest of four sisters all of whom became trained singers; two achieved professional fame: the oldest sister Josepha Weber and the second oldest Aloysia Weber. Her mother was Cäcilia Weber. She moved with the family, first to Munich, then to Vienna, following the burgeoning career of Aloysia. Sophie herself sang at the Burgtheater in the 1780–1781 season, but apparently did not make any kind of long-term success as a singer..."

"...In December 1791, when Mozart died, Sophie was 28 years old, and was the only daughter in the family still unmarried. She lived with Cäcilia, but was frequently present in the Mozart household during the composer's final decline and death, and helped Constanze care for her dying husband..."

"...She was married (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. Haibel, who had already left his first wife in 1804 to run away to Croatia with his lover Sophie, was the cathedral choirmaster in Djakovar. Following Haibel's death, Sophie moved to Salzburg, where Constanze, now widowed from her second marriage, was living. The two lived together until Constanze's death in 1842..."

"...Sophie died in Salzburg in 1846, aged 83..."

SOURCE: Wikipedia contributors, 'Sophie Weber', Wikipedia, The Free Encyclopedia, 14 August 2011, 15:57 UTC, <http://en.wikipedia.org/w/index.php?title=Sophie_Weber&oldid=444818107> [accessed 20 August 2011]