They are the dukes of Montpensier at San Telmo gardens, with their three elder daughters: Isabel and Maria Amalia, and baby Cristina.
And this is a picture of Isabel with her husband Philippe and their children. From left to right: Helena, Louis Philippe, Philippe count of Paris, little Louise, Isabel countess of Paris, Ferdinand and Isabelle. The picture was taken when they were on holidays at Villamanrique de la Condesa.
Given the age gap, I would say the girl on the left is Pss Amélie, later queen of Portugal.
She had a more plump figure than her skinny sister Hélène.