Big Questions

K's been thinking about weighty issues. For the last week or so when we are saying prayers at night, she asks some huge questions. I don't prompt them, I am usually just praying, "Lord, teach K about you. Give her a good night's sleep. Thank you for..." etc. And then she pops in with a doozy of a question. Here are the ones I can remember.
Mom, does God know what Satan is doing?
How do you get to heaven? (she already knew what you needed to believe, she just wanted turn- left- at- the- corner type directions)
How can I be really good all day?
Why do grown-ups lie and say Santa Claus is real? ( Santa Claus is a fun storybook character at my house, he doesn't exist in any other form here)

I am still waiting for H to pop the question about babies. She isn't a naturally curious child, it could be a while. What's a typical age for such things to come up?