We visit Alnwick frequently to see my wife’s family members. We normally stay at “Hardys House”:https://www.northumbria-cottages.co.uk/property/hardys-house, a 3-bedroom house in the centre of Alnwick. It is well-equipped and clean. The prices are reasonable. I can’t recommend it enough, it is well worth visiting. It is bookable through Northumbria Cottages based in nearby Seahouses.