Augustus John was one of Britain’s great painters, particularly renowned for his portraits of contemporaries such as Yeats, Shaw, and his fellow Welshman Dylan Thomas. John led a bohemian life and had many children. Few are aware, however, that he had an older sister, Gwen John, who painted equally evocative portraits. She was born in Haverfordwest, Wales, in 1876, and moved to London to study at the Slade School of Fine Arts. Then it was on to Paris, where James McNeill Whistler became her friend, and Auguste Rodin, her lover. This exhibition presents 70 of the artist’s paintings and drawings, and makes the case for a modern trailblazer too long overshadowed by the men around her. —Elena Clavarino