Where was Shamima Begum radicalised?

Despite the case of Shamima Begum being given much prominence, there has been nothing in the media about the means of her radicalisation at fifteen years of age. Which mosque did she and her family attend? Who preached there? These are questions that need to be answered until the person or persons who led to this woman's predicament and betrayal of her Country of birth are found and tried on inciting a crime.