Another tree nut and peanut allergy here! Definitely mark the allergy on your reservation now, before you leave. Check in with the dining staff when you board and make sure they have the allergy on file. You can pre-order your meal for the first night there as well, so it won't take as long to prepare. (Often the first supper is slow to arrive because they take extra precautions for allergy meals that can delay your order. Thus, the advantage of preordering your meals.) We've had great service and success with our main dining room dinner servers.
If you do not feel confident that your servers understand your allergy and your requests do not not be afraid to go to the Matire'd or Guest Services and be reseated immediately.
We were also told to always avoid the bread at the restaurants. On our second
Disney cruise a lunch waiter said the bread was safe but after my first bite I knew something was wrong and got sick enough to require medical attention. Lesson learnt, don't trust the bread in the restaurants. Ever. Unless it's the allergy-friendly rolls they have, but I haven't seen those since our first
DCL cruise.
Otherwise, our meals were always well attended to in the MDRs, we preordered meals for the next day, and they were able to make some of my silly requests come true, like safe cookies for dessert! (You may know how hard it is to find safe cookies in restaurants, and I'm a bit of a cookie monster.) We've even asked the chefs to surprise us with a safe dessert and we've ended up with everything from chocolate lava cake to multi-layer sundaes (with some sort of pudding instead of ice cream because the ice creams weren't safe), and a crazy sculpture of fruit salad.
Buffets were really good, just ask the chef to come out, walk you through the options, and prepare a plate in the kitchen to avoid cross-contamination. I was pretty happy at the buffets, surprisingly, they were very quick, and always gave me huge portions because I would only ask for one or two things and maybe they thought I would starve... The desserts at the buffet are never safe, neither are the pastries at breakfast.
The quick service places on deck were the same - ask a chef to come out and make sure the ingredients for what you want are safe. Avoid anything pre-prepared like sandwiches (bread!), wraps, or even cut fruit there, as the chance for cross-contamination is pretty high. It can take a really long time for the chef to come out and a really long time after that for them to come back with the ingredients (they had to go down to the galley and check the box) so ask well ahead of time if you want pizza or burgers or whatever, and bring your wave phone, because they'll probably use it to contact you with the ingredients. The fries may or may not be in an allergy-safe fryer for your cruise, so ask first if anything else they are frying that week has nuts in it. We were lucky and could eat the fries and veggie burgers (they were nut-free, surprisingly, and we could have the buns!). The pizza place made us a fresh pizza too.
We've been told to avoid room service as they cannot guarantee safe items will be available and cannot guarantee no cross-contamination. We've never used room service as a result.
Oh, and I had a lovely conversation with a chef one day in the outdoor dining area. He said that most chefs feel bad that guests with allergies cannot indulge in many of the things other guests can. They know food is an important part of vacation and want to give guests with allergies that experience as well. For instance, one chef made me a plate of safe cookies, fresh, to take back to my stateroom. He heard me talking about how I wish there was some sort of safe dessert at lunch and how much I was craving cookies. (I'm a cookie addict, what can I say!) He did this twice during the cruise and it made me feel like a superstar!
Kids clubs mark kids with allergies and will store EpiPens (or other autoinjectors) at check in. If you tell them you don't want your child to have any food, they will honour that request. Thus, do your part and not drop them off during meal times or during food activities (baking cookies). On some cruises they have different colours on the wrist bands for kids with allergies or medical conditions, not sure if this is all the time or just on the Magic.
In port, we typically do not eat anything because we don't know the allergy labelling laws in other countries. On
Castaway Cay you can have your preordered lunch on the ship or at Cookies BBQ. Talk to your server the night before to make arrangements for when and where to have lunch. If you are on a tour that includes a meal, mark the allergy on that reservation too, and talk to your head server the night before to see if they can send along a safe meal. Otherwise, we don't eat on excursions and will bring snacks from home to eat instead to tide us over.
Have a safe and fun vacation! Preorder allergy-safe meals the day before, check ingredients everywhere else, avoid the bread, and listen to your spidey sense.