I would respond to Anonymous with this answer: The evaluation of your parenting is whether you are being faithful to God's word and His direction. You cannot judge yourself to being doing well or poorly based on your own thoughts or by comparing to other children. Ask yourself these things:
1. Am I personally seeking God's word to guide my own life?
2. Am I praying daily for my child/
3. Am I striving to train my child in God's word?
4. Am I lovingly correcting my child in errors and lovingly encouraging my child in right decisions?
5. Am I willing to ask God's forgiveness for all my sins, and to acknowledge my need to do so to my child?
Will you always answer yes? Somedays you will consider yourself doing well on all of these, somedays you will feel like a total failure. However, I would encourage you to look across the lifetime of your child. If your child is 8, then you've had 2922 days or 70128 hours. While you want to make the most of each, don't think that one bad day will undo all of those. And realize that you will be a lifetime influence on your child.