Can I use a French embassy’s income declaration for my mother’s O visa application in Thailand?

A user asks about their mother's potential relocation to Thailand after their father's passing. Currently on a DTV visa in Thailand, the user's mother lacks the 800,000 baht necessary for a retirement visa. She might rely on the French embassy's income declaration, which is based on honor without verification. The inquiry involves whether this declaration can be used for her initial O visa application upon her arrival in Thailand without a visa, and if she will meet the financial requirements by the end of the year. Responses suggest checking with the local immigration office, utilizing a tourist visa initially, or ensuring proper documentation of her income before applying.