 Pregnant and often ill , Mary Godwin had to cope with Percy 's joy at the birth of his son by Harriet Shelley in late 1814 and his constant outings with Claire Clairmont . She was partly consoled by the visits of Hogg , whom she disliked at first but soon considered a close friend . Percy Shelley seems to have wanted Mary Godwin and Hogg to become lovers ; Mary did not dismiss the idea , since in principle she believed in free love . In practice , however , she loved only Percy Shelley and seems to have ventured no further than flirting with Hogg . On 22 February 1815 , she gave birth to a two @-@ months premature baby girl , who was not expected to survive . On 6 March , she wrote to Hogg : 
