Complex sentence: Included in the photograph are William Ewart Gladstone and his wife Catherine and daughter Mary, as well as the Earl and Countess of Rosebery and the Countess's cousin Baron Ferdinand de Rothschild.
Split into simpler sentences: Included in the photograph are William Ewart Gladstone and his wife and daughter Mary Gladstone, and the Earl and Countess of Rosebery. Also pictured is the Countess's cousin Baron Ferdinand de Rothschild.