My gf went for interview and was ask only one question and was denied. She told me that the guy ask everyone the same question and denied each one while she was there.
Do not mention family in USA.
Must have strong tides to Thailand
You cannot go in only she is allowed in.
Make sure she has money when she goes sometimes they make you get new picture than tell you denied
Good luck.
We since have applied for K1 visa they are saying 15 to 18 months to get interview