 Mary Shelley 's last years were blighted by illness . From 1839 , she suffered from headaches and bouts of paralysis in parts of her body , which sometimes prevented her from reading and writing . On 1 February 1851 , at Chester Square , she died at the age of fifty @-@ three from what her physician suspected was a brain tumour . According to Jane Shelley , Mary Shelley had asked to be buried with her mother and father ; but Percy and Jane , judging the graveyard at St Pancras to be " dreadful " , chose to bury her instead at St Peter 's Church , Bournemouth , near their new home at Boscombe . On the first anniversary of Mary Shelley 's death , the Shelleys opened her box @-@ desk . Inside they found locks of her dead children 's hair , a notebook she had shared with Percy Bysshe Shelley , and a copy of his poem Adonaïs with one page folded round a silk parcel containing some of his ashes and the remains of his heart . 
