A portrait of two standing women, Jenny Lind on the left and Marietta Alboni, Countess Pepoli (née Maria Anna Marzia) on the right. They wear long dresses and stand beside a column base and in front of a cloud backdrop.
http://en.wikipedia.org/wiki/William_Edward_Kilburn
http://www.biography.com/people/jenny-lind-9382597
http://www.encyclopedia.com/doc/1O76-AlboniMariettaMariaAnnMrz.html
http://www.npg.org.uk/collections/search/person/mp08120/william-edward-kilburn
http://www.npg.org.uk/collections/search/portrait/mw58425/Jenny-Lind-Marietta-Alboni-Countess-Pepoli-ne-Maria-Anna-Marzia?search=sp&sText=daguerreotype&firstRun=true&rNo=11
http://www.photolondon.org.uk/pages/details.asp?pid=1246
https://en.wikipedia.org/wiki/Jenny_Lind
https://www.ram.ac.uk/museum/collections/collections-highlights/performers-collections-and-archives/jenny-lind-archive