Short answers, pulled from the story.
Maria Constanze Cäcilia Josepha Johanna Aloysia Mozart entered the world on the 5th of January 1762 in Zell im Wiesental. This small town sat near Lörrach within what is now Baden-Württemberg, southwest Germany.
Mozart decided to marry Constanze that same day in a side chapel of St Stephen's Cathedral on the 4th of August 1782. She later married Georg Nikolaus von Nissen legally in 1809 after traveling to Pressburg today known as Bratislava.
Constanze Weber received extensive training as a musician throughout her youth and played a direct role in shaping specific compositions by Wolfgang Amadeus Mozart. She sang in the 1783 premiere of The Great Mass in C minor held in Salzburg and inspired Fantasy and Fugue K. 394 specifically for her.
She obtained a pension from the emperor to support herself and children following his death in 1791 leaving significant debts behind. Constanze organized profitable memorial concerts including a benefit performance on the 29th of December 1794 at the Kärntnertortheater in Vienna which eventually made her wealthy.
Constanze published their joint work with second husband Georg Nikolaus von Nissen in 1828 two years after he died. They settled permanently in Salzburg in 1824 where both worked on this biography that shaped public perception of Mozart for decades afterward.