Age that a Thai child can register land

Thanks in advance.

Does anyone have any idea at what age a Thai national child can place land in their name? I believe it is 16 but what sort of cost would it be to have some sort of agreement where the child say age 12, has the land in mothers name until the legal age.

Reason being have a child born Uk, who has also Thai nationality. Would rather the land in her name than mothers for her future.

Cheers