This is a photo of actress Agnes Burdett (stage name) After much searching this was confirmed to be one and the same as Sarah Hart, sister in law to Arthur Francis Wileman. Arthur’s wife Amelia Hart had been in a rather nasty court case with her former husband in which reference  to Sarah and Agnes appeared in different articles and  this is where confusion arose.
Apparently she was quite well known and you can find references to her performances in different London theatres.

Agnes(Sarah) was born in 1832
The photo was taken approx 1860 -1865

Most actors and actresses in the Victorian era had what was called a ‘carte visite’ which often depicted them in costume.

The picture is an albumen print made from a glass negative attached to a  stiff card backing. The photograph can be found in the V&A museum Guy Little collection. 

Photograph provided to wbrq02.com courtesy of the Victoria and Albert Museum