Ask an Immigration Solicitor. Get an Answer ASAP.
Good afternoon, Does your mother have a permanent residence, settled status in the UK?
Alright. Your mother must apply for a settled status first, once it is approved, she can apply to be naturalised as British After one year unless she is married to a British Citizen.
All right, she must apply for a settled status first and after naturalisation as a British Citizen.
Most welcome! Good luck