1860 (2 November) Marchioness Townshend by Camille Silvy wearing a big paletot
It looks like 2 November was the day the Townshends visited Camille Silvy's studio. Her maiden name was Elizabeth Jane Stuart. Her article in thepeerage is here.
From Paul Frecker; sepia tone removed by gogm (and re-added to the border only with Photoshop).