Yeah, the immigrant issues complicate LW1, so I will just add: LW, they have picky eaters in Taiwan, too. She might not like a lot of things that are considered "Chinese food" but there are probably foods that picky eaters eat in Taiwan that she would be okay with (and are very similar to foods she eats here.) Do some looking at foods she can eat that might overlap with things you can get in Taiwan, and work together on figuring out how to make sure she can eat while she's there, and what local foods might be things she would like to try *before* the trip, so that she can have some definite OK options she knows about. Talk through what things she could request at places like a restaurant that might help (like, for me, "hold the sauce" helped a lot with Chinese food; or if it's mostly a texture thing, avoiding most vegetables for awhile won't kill her.)

Also, be prepared to be a barrier between her and any relatives in Taiwan who aren't going to be willing to work with her.