@John *********
I assume this is translated into Thai. There are translation services open on Saturday, the day you arrive, and it should only take a few hours for them to translate it, as it is just a marriage certificate, not some long multipage document. Make a copy of the document, and use that for the translation as soon as you get here. It should be done by Monday, then you take this translation to the ministry of foreign affairs at Chaeng Wattana on Pak Kret road building A to get it certified and stamped as being accurate. This takes a short time based on the queue, with enough time to go back to the translator for any corrections. This gets you to Tuesday for your embassy appointment, and notary service. Now you're ready to head to her Amphur on Wednesday. This should involve registering the marriage with the Amphur, and why you need the certified marriage certificate, and the certified translation, then the processing of the name change, that should be done fairly quickly. Make sure you get a color copy of your marriage certificate to get certified at the embassy, as you do not want to be giving the Amphur your original marriage certificate, as they keep it.