The Interior of the Stables at Carton, County Kildare; a Liveried Groom, Lord Charles William FitzGerald, and his Sister Lady Jane Seymore FitzGerald, c. 1825 - George Nairn (Irish, 1799-1850).
This painting was featured at the Art Institute of Chicago's Ireland: Crossroads of Art and Design, 1690–1840 exhibit in early 2015.
The subject of the art is thankfully named in the title, so we can see what happened to Lord Charles William and his sister Lady Jane. I really love this kind of investigation into postcards, either if it is the subject of the postcard or was the sender of an old, previously sent postcard I purchased.
Lord Charles William FitzGerald, pictured upon the white horse in the painting/postcard was born March 30, 1819 and passed away February, 10 1887. He was 4th Duke of Leinster and, until 1847 stylized as Marquess of Kildare. He would have 15 children, with the last one dying in 1955. (via Wikipedia.)
Lady Jane Seymore FitzGerald, pictured just below the white horses nose, was born February 5, 1824, making her about 1 year old in this painting if the date is correct. She would marry British Conservative Politician and Member of Parliament George William John Repton (1818 – August 30, 1906). She would die on November 3, 1898.
The estate where the painting was made, Carton, was also where Lord Charles William FizGerald would live and pass away. In the 2000's much of the estate was transformed into two golf courses and the house into a hotel. (according to Wikipedia.)