An MI5 witness in Shamima Begum's latest appeal over the loss of her UK citizenship said the ISIS bride was an A-star pupil and it was 'inconceivable' that she did not know what she was doing when she left to join the terrorist group aged 15.But her lawyers have argued that Ms Begum, now 23, was influenced by a 'determined and effective ISIS propaganda machine', and should have been treated as a child...