I CAN STAND (I just don't know it)

Today Sophia was standing at her bookshelf taking books off and looking at them. All of the sudden Joel and I look over and there she is standing reading a book. She stood there for about a minute or so and then went to the bookshelf and got another book. She had no idea that she was standing. She will NOT let go of our fingers or even try to stand on her own. She can do it. She just lacks confidence.