We've had a wonderful experience with Broomwood Montessori https://www.broomwoodmontessori.com
The most wonderful, nurturing staff, great facilities including an enormous hall so the children get playtime in all weathers, and a very cute nature garden.
It is small, so perfect for quieter children who might get overwhelmed in big groups. Our son absolutely thrived...
They went above and beyond during covid and lockdowns, and are well-regarded by local schools. Highly recommend it