I have always wondered what documents immigration might ask for an extension "to be under the maintenance of a child" as per clause 2.18(5) of Police Order 327/2557 (2014) (highlighting in bold is mine)
Immigration Bureau Order 138/2557 (2014) gives full information about the required documents only for the first paragraph of clause 2.18(5) but indicates the requirement for an affidavit from the the child to confirm the parental relationship of the foreigner with the child.
There is no harm in your inquiring from your local immigration
Removed an off-topic post.
