Your stay can be extended one year on the basis of being a Thai citizen (father Thai makes you that). Obviously Consulate considers you a citizen with whatever information you provided them. But suspect Immigration will want report of birth to actually to prove father Thai to extend stay.

Your stay can be extended one year on the basis of being a Thai citizen (father Thai makes you that). Obviously Consulate considers you a citizen with whatever information you provided them. But suspect Immigration will want report of birth to actually to prove father Thai to extend stay.

As Lop said, if you organise that you have a Thai birth certificate issued to you and your child by the consulate, then that will be 'evidence' enough for you to qualify for an extension of your 90 day entry for the both of you at least.