When Sophia Alexandra Hall received the response to her application for the University of Oxford in 2015, she opened it in front of everyone at her school. “I ran into the canteen and burst into tears,” she says. “I was sobbing, and I remember my headteacher saying: ‘Stop crying – you got into Oxford!’ No one at social services believed me.” As a care leaver, the odds of Hall making it to university, let alone Oxford, were very slim. As…