Need help with crazy dog?

We have almost 6 year old female German Shepard and we just had a baby in January. Our baby is starting to move around on the floor and our dog "Angel" paces the floor and pounces on things on the floor that aren't really there. She just runs from one room to the other and pounces, then runs to the other room and pounces. I know we should have tried training her before we had the baby, but we thought she would outgrow this in her old age, but she seems to have not. I don't want her pouncing on the baby on accident or running her over. How do we calm Angel down? We've tried almost everything to try to train her...but she is not a very smart dog. We think she was inbred, because she doesn't listen very good and doesn't remember where the door frames are or the furniture is so she hits her head on them a lot! She also tries to plow you over to get outside when you are going towards the door. How can we stop that? Thanks for your help!