T.L.
Hi M. let me first say that I think it is wonderful that you are so attentive to the needs of your step son and your daughter. I have worked with autistic children in the past and I currently work with children that are oppositionally defiant. Well let me tell you that tone of voice, consequences, and redirecting works great with both of these types of children. Without yelling you can have a stern voice and command your son to move away from your daughter. Also, when they are playing together you should at least until you see a noticeable change in behavior, play with them so that he can see how to handle something smaller. Doing organized play with both children can benefit them immensely. Time-outs are never out of order. If he pushes her down or hurts an animal or breaks a toy, you can definitely direct him to a special time-out area where you have a task (that is not fun)for him to do ex. seperating beans or moving objects from one place to another for the expected time. I hope that you can find a suitable way to curb this behavior. Good luck and God Bless