 During the period 1827 – 40 , Mary Shelley was busy as an editor and writer . She wrote the novels The Fortunes of Perkin Warbeck ( 1830 ) , Lodore ( 1835 ) , and Falkner ( 1837 ) . She contributed five volumes of Lives of Italian , Spanish , Portuguese , and French authors to Lardner 's Cabinet Cyclopaedia . She also wrote stories for ladies ' magazines . She was still helping to support her father , and they looked out for publishers for each other . In 1830 , she sold the copyright for a new edition of Frankenstein for £ 60 to Henry Colburn and Richard Bentley for their new Standard Novels series . After her father 's death in 1836 at the age of eighty , she began assembling his letters and a memoir for publication , as he had requested in his will ; but after two years of work , she abandoned the project . Throughout this period , she also championed Percy Shelley 's poetry , promoting its publication and quoting it in her writing . By 1837 , Percy 's works were well @-@ known and increasingly admired . In the summer of 1838 Edward Moxon , the publisher of Tennyson and the son @-@ in @-@ law of Charles Lamb , proposed publishing a collected works of Percy Shelley . Mary was paid £ 500 to edit the Poetical Works ( 1838 ) , which Sir Timothy insisted should not include a biography . Mary found a way to tell the story of Percy 's life , nonetheless : she included extensive biographical notes about the poems . 
