George Sand at 60
These photos of Sand were taken by Nadar (Gaspard-Félix Tournachon) in 1864 (when she was 60 years old). She outlived them all, except Liszt, and died at 71 in 1876.
Below is a portrait of Sand by Achille Lemot from 1870 - presumably based off that photo - and below that a wild hair photo by Nadar, possibly from the 1864 series.