What size children's windsurf sail should I have?

Child weight Sail size
13.6 - 20.4 0.8 m2
18.1 - 27.2 0.8 - 1.5 m2
27.7 - 31.8 1.5 - 2.0 m2
32.2 - 36.3 2.0 - 2.5 m2
36.7 - 40.8 2.5 - 3.0 m2
41.3 - 45.4 3.0 - 3.5