I would agree with the first part of AU's writeup, but the last point I don't agree with. Being created in God's Image, Imago Dei, doesn't always mean God's physical image. Some scholars and theologians have argued that being created Imago Dei means the ability to think, comprehend and know God. Being created in the image of God provides us the ability to know there is a God and have fellowship with Him.
As far as I know, God is never described as a person, with acutal physical descriptions, thus the whole part about God having two eyes, two ears, etc might not be the case. The "person" of God is Jesus Christ. After His resurection, we know that He had a body that was physical just perfect and we know that He ate and drank with the disciples.
So back to the main issue here, Did Adam and Eve have belly buttons? I would lean more towards the no side of things. As mentioned previously, I think, the belly button comes from the umbilical cord and if you have no mother, then there is no reason the belly button, case closed