Domalino is stuck where you are stuck.
No, I just understand a court ruling, unlike you or whatever hack news site you're quoting.
This is the actual decision from the chief justice.
The Supreme Court unanimously allows the Secretary of State’s appeals and dismisses Ms Begum’s cross-appeal. The result is that Ms Begum’s appeal against the LTE decision is dismissed, her application for judicial review of the LTE decision is dismissed, and her application for judicial review of SIAC’s preliminary determination in her appeal against the deprivation decision is dismissed.
This is what they decided.1) Her appeal against the LTE decision is dismissed (That's her Leave to Enter deicison - can she come back to the UK).
2) She doesn't have grounds to appeal the LTE decision.
3) She can't appeal the SIAC's preliminary determination (That's the decision to revoke her citizenship) against her.
Now the 2 highlighted words are important because the reason she can't appeal the SIAC decision is the same reason Man City's first appeal to CAS was rejected - you can't appeal a decision that's not final.
In fact to quote the chief justice
Her appeal against the deprivation decision not having been finally determined, Ms Begum did not have a statutory right of appeal to the Court of Appeal.
That right there, is the Chief Justice of the Supreme Court saying that Shemima Begum's citizenship has not been finally determined.So no, you're not right when you say she's not a British citizen. It's not a "fact".