Wise and kind girl! :)
My daughter officially came to terms this year about Santa as well. God on the other hand; well, I encourage her to believe in as much as I can.
I stopped believing in God years ago as well and in fact went on my own journey to understand and define the world around me. I felt like I searched for every reason under the sun to explain how God was not real. It didn't work.
For every explanation I came up with there were still more questions unanswered. For example the cliche one (but quite undeniable), If there's no God and the universe was created in the Big Bang, then what caused the Big Bang to occur. Try explaining that without bringing up God. The answer nothing just never sat well with me. I'm quite a logical and sciency guy - something never comes from nothing.
As a middle aged adult, I found my way back to God. He is real. I know it for certain. The only problem I have is trying to get straightened up in my ways.
All the best. Wish you luck in your journey. All I would say is keep asking questions.
Oh and I forget to comment...
Those cookies look very tasty. I'm sure "Santa" enjoyed them. The carrots, I'm not so sure about though. :)