Alexander's brother, her uncle Hugh Falconer, invited her along on a long tour of Italy and France in September 1858, during which they met his friend, the science writer Mary Somerville, and she became his assistant, secretary and hostess until his death in 1865.
During her travels with Hugh Falconer, "Grace collected fossils at several localities, drew museum specimens, and copied cross-sections" for her uncle, "learning all the while".
[2] Prestwich began writing during the 1870s, publishing two anonymous novels and a series of articles explaining geology in Every Girl's Magazine and Good Words.
[4] Under Falconer's tutelage and as a result of her own expertise and intellect, she had become a geologist in her own right at a time when women were still denied access to academic education and degrees.
The president of the Geological Society in London recorded on her passing that only her female sex had precluded Grace Prestwich from being elected Fellow.