Maybe it'd help if I shared a situation from the other side?
When I was in Kindergarden, all my classmates got those little individual packages of oreos to take home. (This was when oreos were still made with animal shortening). When my mom picked me up, she told me I couldn't have them. Of course, I was a bit upset, but she explained that they were made with animal fat. Of course, by five, I knew why we didn't eat animals, and I dropped it, and was content to give them to a friend. My mom, being the wonderful person she is, probably gave me homemade cookies when we got home, but I don't remember if she did or not.
It didn't scar me for life. As long as you are sure you explain *why* you don't eat something, you're daughter will be fine.
P.S. I also remember at lunch in first grade (or second?) one of my friends trying to give me peperoni, and me getting really frustrated, because I couldn't make anybody understand that peperoni comes from piggies. lol
Who needs sleep when we've got love?
Who needs keys when we've got clubs?
Who needs please when we've got guns?
Who needs peace when we've gone above?