Legal Question in Family Law in California

If the marriage is legal under the laws of the place where the marriage takes place, it is automatically considered valid in the U.S. unless if violates some crucial public policy of the U.S. that would make it totally void here - such as a bigamous or incestuous marriage. You should, however, be prepared to provide proof of the marriage. So it would be a good idea to have certified copies of all marriage documentation that is issued in connection with the marriage in Thailand, AND have certified translations made. The U.S. Embassy in Bangkok or a U.S. consulate in Thailand should be able to help you. If they cannot help you for some reason, I have a loose association with a law firm in Bangkok and would be able to assist you with obtaining a legally valid translation. But try the U.S. government options first - their help is free.