It's sad for your daughter to be losing some of her innocent happiness, but no one can remain naive forever - in fact it is dangerous to! Don't feel bad that she sees you being anxious, or upset. I think it's a wonderful skill you can encourage in her to be able to empathize with others' feelings. You're also teaching her that feelings and emotions are important, and that it's okay to feel things, even when the feelings are scary. You can also teach her that it's good to talk about feelings, and that it's okay to ask for help with them if they become overwhelming. These are wonderful things to share with your daughter, in my opinion.