She will win on appeal- because the decision is politicised and not based on due process . A groomed 15 yr old British citizen leaves the UK. British nationality stripped and her baby left in limbo many other offenders who have committed paedophilic acts , serious drug offences and even many ISIS fighters have been allowed back into the UK. So this will be interesting
There are various criteria that have to be met if the teenager is to be prevented from returning to the UK.