I think Truths is right; I'm of a similar age and have never seen a beheading video or any violent IS footage, despite being an avid consumer of current affairs. Having seen how easily various conspiracy theories took hold of formerly clear-thinking people during the pandemic, why are we surprised that radicalised young people were able to discount the portrayal of IS in the western media, rationalising it like "...Well, that's what they want people to think... They would say that, wouldn't they... They are serving their own agenda..." Phrases like these have caused untold suffering in the post-truth West. All it takes is a bit of mental gymnastics and a suspension of critical faculty in place of faith, which is a key feature of most organised religion, let alone radicalised groups.
I work with refugee communities and, as stated in the podcast, it is not uncommon for young people in war zones to give an exaggerated impression of their own resilience. I see this a lot in the children and young people I work with; heartbreaking, life-changing stories or snippets of gruesome, violent events passed off with a shrug, as if in passing, with a smile, even; "Don't worry about me, it's OK." I'm not at all surprised that Shamima, in the situation she found herself in, giving that first interview, may have come across as aloof or detached from the horrors of the regime.
I think Shamima should be permitted to return to Britain, her citizenship reinstated, and the extent of her culpability investigated here under the close scrutiny of professionals and agencies expert in radicalisation, trafficking and coercive control and who able to advocate for her interests.