 Mary 's earliest years were happy ones , judging from the letters of William Godwin 's housekeeper and nurse , Louisa Jones . But Godwin was often deeply in debt ; feeling that he could not raise the children by himself , he cast about for a second wife . In December 1801 , he married Mary Jane Clairmont , a well @-@ educated woman with two young children of her own — Charles and Claire . Most of Godwin ’ s friends disliked his new wife , describing her as quick @-@ tempered and quarrelsome ; but Godwin was devoted to her , and the marriage was a success . Mary Godwin , on the other hand , came to detest her stepmother . William Godwin 's 19th @-@ century biographer C. Kegan Paul later suggested that Mrs Godwin had favoured her own children over those of Mary Wollstonecraft . 
