Luck be a lady - Anna King

When 14-year-old Rebecca's parents die of smallpox she and her brother and sister must leave their smart home in Kent for the more poverty-stricken conditions in London's East End. After initial trauma, they adapt to poorer living conditions and grow to love the area.
Five years on, aged 19, Rebecca meets Jimmy Jackson, born in Bow and now a successful bookmaker. They are attracted, but when their relationship grows to love, an old flame of Jimmy's turns up, producing a son he didn't know he had. Young James and Jimmy get on well, his old flame decides to take herself off to enjoy her life without them, and Rebecca and Jimmy's relationship takes off again.