There's hope yet:
//Is she entitled to Bangladeshi citizenship?
Expert lawyers with experience in Bangladeshi citizenship cases have told the BBC that under Bangladesh law, a UK national like Ms Begum, if born to a Bangladeshi parent, is automatically a Bangladeshi citizen. That means that such a person would have dual nationality.
If the person remains in the UK, their Bangladeshi citizenship remains in existence but dormant.
Under this "blood line" law, Bangladeshi nationality and citizenship lapse when a person reaches the age of 21, unless they make efforts to activate and retain it.
So, it is Ms Begum's age, 19, that is likely - in part - to have given Home Office lawyers and the home secretary reassurance there was a legal basis for stripping her of her UK citizenship. //
https://www.bbc.co.uk/news/uk-47310206