Schluss is the last Übungsstück (Exercise) in the book 14 Klavierstücke, written in 1823 by Fanny Hensel (née Mendelssohn).
 
Listen to Heather Schmidt’s 2010 Naxos recording (2m 15s) of Schluss here on Spotify (or here on YouTube).
 
This piece is from a series of piano pieces she wrote between 1822 and 1824, aged around 18. Schluss, the last piece in her original manuscript, translates as Ending or Conclusion. It is a moot point as to whether Fanny is now called Fanny Mendessohn Hensel or just Fanny Hensel. 
 
Fanny Mendelssohn was born on November 14th 1805 into a wealthy Jewish/Christian family in Hamburg, Germany. She was a prodigiously gifted piano player as a child, composing early in her years. Her adult life was defined by the social and gender conventions of her time; her father appreciated that music may become her profession but urged her that it should only be an ornament, not the root of her being and her doing. As both a woman and musician, she nevertheless pursued her musical talent and battled contemporary prejudice: "It must be a sign of talent that I do not give up, though I can get nobody to take an interest in my efforts." She was acknowledged as a better pianist than her more famous (and four years younger) brother Félix Mendelssohn, but found herself in his shadow. She only performed in public three times in her short life.
 
Fanny met Wilhelm Hensel when she was 16 but waited until she was 24 years old, in 1829, to marry the impecunious artist. She continued to compose and her piano work, Das Jahr (The Year) is considered to be one of the great piano suites of the 19th century. Her first publication was in 1846, just a year before she died. 
 
Fanny composed 450 musical works (including over 250 lieder, plus piano études, sonatas and quartets, string quartets, choral works) but died young from a stroke in 1847, aged 41. Her brother died of similar apoplexies six months later, aged 38, as had both their mother, father and grandfather. Felix once described death as a place ‘where it is to be hoped there is still music, but no more sorrow or partings.’ The Nazis may have tried to erase the Mendelssohns from German history, but their music happily now lives on.
 
A longer biography is here at fannyhensel.de
Manuscript source: Staatsbibliothek Berlin
 
Fanny: The Other Mendelssohn film documentary review [click for link] - a tale of two siblings. The salutary tale of a neglected composer, neatly told. The Guardian review of the above 2023 film.
 
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The painting on the cover of this Fullscore publication is Die Gartenlaube by Robert Pötzelberger. It depicts Fanny and Felix Mendelssohn at the piano.