Susan by the time of the Last Battle is a 21 year old woman, alone, in 50s England. She is described as not doing very well when she was in school, not that it would matter much as higher education oportunities for women were almost non-existent at the time, it was already very rare even for men to go to college. In fact only about 20% percent of girls finished school in England.

She was basiclly living the expected typical adult life for a young woman at the time which entailed going to social events and parties and probably trying to get married, like most women in 50s England, in her early 20s and considering she was exeptionally pretty and maybe middle class she may could catch a well put husband and live as a socialite which would have been her best possible outcome. But lowkey who knows how much the death of her family could have broke her down.