Stepparent adoption, is a much easier process. Since the child and stepparent have been living together, the parent has been supporting the child, the two have formed a bond, most states do not require homestudies and or background checks for a stepparent adoption. Make sure that you get certified copies of all of your birth certificates, you will need them. Your process should be fairly simple since you are not needing to seek a TPR from another parent.
This adoption should go much smoother for you!!!
http://stepparent.adoptionblogs.com/