I can find almost nothing about her, although numerous photos and portraits exist.
Lucemagazine had this about Anna Morosini (translated from Italian by Google), "The most beautiful women of the upper class of the time were portrayed on his (Vittorio Matteo Corcos’) canvases: the Countess Anna Rombo Venetian Morosini hailed as 'the most beautiful woman in Italy;' Yole Biaggini Moschini, sophisticated muse of Antonio Fogazzaro; the soprano Lina Cavalieri, 'Venus in the ground' for D’Annunzio; or even the American dancer Isadora Duncan.”