I think a letter from you to the consular officer for your wife to take with her to the interview may be helpful. Tell them about your situation, your future plans together, and give them whatever assurance you can that she will be returning to Thailand.
My situation was a little different because I was living in Thailand when my wife applied for a tourist visa. She said the interviewing officer seemed very interested in a letter she took with her written by my brother welcoming her to the family and saying how much everyone was looking forward to meeting her.
She didn't have any money, property, a good job, or children but her visa was approved.