Questions from a 3 yr old

So, we were getting home after dark one night, and Hailey asked,
"Mom, is the moon going to bed soon too?"
Mostly because I didn't know how to answer that or really want to try to explain to a 3 yr old at that point, I simply answered, "Probably soon!"
Hailey looked up in the sky and saw the moon--but it was just a small sliver of the moon.
"Mommy, why is the moon lying down?" she asked!!