 Mary Shelley lived a literary life . Her father encouraged her to learn to write by composing letters , and her favourite occupation as a child was writing stories . Unfortunately , all of Mary 's juvenilia were lost when she ran off with Percy in 1814 , and none of her surviving manuscripts can be definitively dated before that year . Her first published work is often thought to have been Mounseer Nongtongpaw , comic verses written for Godwin 's Juvenile Library when she was ten and a half ; however , the poem is attributed to another writer in the most recent authoritative collection of her works . Percy Shelley enthusiastically encouraged Mary Shelley 's writing : " My husband was , from the first , very anxious that I should prove myself worthy of my parentage , and enrol myself on the page of fame . He was forever inciting me to obtain literary reputation . " 
