16 yo daughter is a British citizen with a British passport. She was born in UK. Both parents are British citizens with British passports, and both born and (mostly) educated in UK. Whole family are native English speakers.
Daughter attends high school in another country. Unfortunately (for complicated and partly Covid reasons) we will be unable to move back to UK in time for her to spend 3 years in UK to be considered as a British resident and qualify for non-international university fees. International fees are beyond our reach. Daughter is certain to want to attend university. University is not an option for her in our current country.
Plan B is to finish high school where we are now, and then at the age of 18 she will move to UK and spend three years (working? Doing something useful?) and then to apply for university aged 21.
That's the backstory in a nutshell. It's very complicated and I've left out lots to avoid writing a book.
Here's my question: How do I find out for certain that as a British citizen with 3 years of residency in UK she will DEFINITELY be eligible to be treated as a non-international student and thus able to afford tertiary education? Where do I find this information for certain?
Many thanks if you can help point me in the right direction.