I found six photographs showing Elisabeth and Franz Joseph together. Unfortunately I wasn't able to scan one of them.
The famous family group (Schönbrunn, 1859):
standing: Franz Joseph, Ferdinand Max, Charlotte of Belgium, Ludwig Victor, Carl Ludwig
sitting: Elisabeth with Rudolf and Gisela, Sophie, Franz Carl
Elisabeth (left, on horseback) with Franz Joseph (right, on horseback) and Napoléon III. (standing next to Elisabeth's horse) and Eugénie (in the middle, on horseback) - Salzburg, ca. 1867
In 1888 the statue of Maria Theresia was unveiled in Vienna. Elisabeth and Franz Joseph are in this pic, too. The author Gabriele Praschl-Bichler thinks that Elisabeth is the woman in the middle of the picture who has a black fan in her hand. I don't think so, because this woman is wearing a white dress - and as you know, Elisabeth has only worn black since her son Rudolf commited suicide.
Elisabeth and Franz Joseph somewhere in Hungary, 1896