Talented sister we never heard of - why?

Hello! Did you know that Wolfgang Amadeus Mozar had a very tallented sister?? 

• Maria Anna Walburga Ignatia Mozart 

Maria, niknamed Nannerl or Marianne , was an older sister of one of the most popular musican that everybody heard of. She was born 30 of July, 1751, 4 years before Wolfgang was born.
When she was seven years old, her father Leopold Mozart started teaching her to play the harpsichord( instrument played by means of a keyboard). She was a child prodigy. Leopold took her and Wolfgang on tours of many cities, such as Vienna and Paris, to showcase their talents. She was noted as an excellent harpsichord player and fortepianist. At three, Mozart was inspired to study music by observing his father's instruction of Marianne; he wanted to be like herowever, because of the society back then, it became impossible as she grew older for her to continue her career any further. Thats so stupid! Just because she is a girl! 
According to New Grove, "from 1769 onwards she was no longer permitted to show her artistic talent on travels with her brother, as she had reached a marriageable age". Wolfgang went on during the 1770s to many artistic triumphs while traveling in Italy with Leopold, but Nannerl stayed at home, in Salzburg, with her mother. 
-------- later years --------
Marianne's husband died in 1801. She returned to Salzburg, accompanied by her two living children and four stepchildren, and worked as a music teacher.

* What do you think about this? I think its very unfair and that girls and women deserved better! 😊