Archduchess Mathilda of Austria
Archduchess Mathilde Marie Adelgunde Alexandra of Austria (25 January 1849 – 6 June 1867) was a member of the House of Habsburg-Lorraine as the daughter of Archduke Albert, Duke of Teschen. She was intended to become the Queen of Italy as the wife of King Umberto I, but her early death prevented the marriage.
Source: Wikipedia — Archduchess Mathilda of Austria (CC BY-SA 4.0)