[LadyMage]

Sugar free and vegan - I don't think you're going to find candy that will fit that bill that won't be completely gross. Some potato chips or something along those lines maybe. Perhaps instead do a non food option? Stickers and temporary tattoos, pencils. Google the teal pumpkin project, they are run by an agency that helps research food allergies, they have lots of ideas on what can be handed out that would be inclusive of kids with allergies who can't have candy, as well as other specialty diets, like those who are vegan.

Not sure how sugar isn't vegan though. I know a lot of white sugar uses bone char in the refinement, but there are companies that don't.