She's allergic to several things added to color foods...but they're in surprisingly more things than you would think.
Food grade colorants are also often added to make ups, facepaints, lotions, and she reacts even in topical (skin) applications. she's allergic to titanium dioxide too (which sadly, yes ,they do put that in foods) so sunscreens can be an issue too. We can control the topical issues on vacation...but the food ones get tricky. She's 9 and just wants to be able to have fun and enjoy things like her younger brother and sister can.
We'd need them to access their ingredient lists, not just the common allergy info that companies often put on a spreadsheet.
Cross contamination isn't usually an issue. It's getting them to actually look at the ingredient info, instead of overacting and saying "it could have those colorings so she can't have it"(which is a reaction we get a lot).