I feel for your daughter. I have CD, lactose intolerance, and histamine intolerance. I regularly use the Find Me Gluten Free app. There is also a website, but be aware that not all restaurants are listed on the website, and you can't use the map feature unless you purchase the subscription. I purchase a yearly subscription because we travel enough to make it worth it for me. FMGF only covers the gluten, but I have found that restaurants that understand celiac disease usually also understand and accommodate other food intolerances well.
I do a lot of research online before our trips using Google Maps and searching "gluten free" or "gluten free restaurant." There are some travel blogs such as Wheatless Wanderlust that I visit for ideas. I also conduct a Google search for something such as "gluten free restaurants in Paris" and see what comes up.
Good luck, remember to bring snacks, and enjoy your trip!