These. If you have smart phones, you may want to have those words and phrases programmed into them. Make sure you also have something written in Thai explaining that she has allergic anaphylaxis in case you need to communicate with emergency responders. I.e., get her medic-alert card translated into Thai. Also, bring extra EpiPens as they are pretty expensive in Thailand. You may be able to get them OTC, but better to bring an Rx just in case.

Will you be staying at major, international resorts? If so, this is something they should know how to handle. You may wish to limit most of your eating to the major international hotels for things other than fruits, and possibly places that specialize in vegetarian food. Even if you successfully convey the danger to a street food vendor, the risk of cross-contamination is great.

I'd also alert your own hotel(s) in advance of arrival via email, and then also communicate face-to-face with the chef and the F&B manager once on site.

Learn to recognize the written Thai words for shrimp, lobster, etc. (assuming her allergy is to crustaceans rather than mollusks), and look for that on condiment bottles, etc.

Finally, you should make sure you know how to call emergency services from your cell, and also be able to communicate to bystanders that you need emergency assistance, just in case.

Try not to worry too much. Be safe and have a great visit!