Morgan and physical therapy

I got some good feedback today from the physical therapist. Basically Morgan is at a 4-6 month developmental age. (She was 9 months old on the 11th.) The physical therapist said Morgan's main problem/delay is lack of muscle development. She needs to strengthen her trunk/core, her arms and her legs. It's not a problem that was caused by anything, but more that she just hasn't developed like she should have. It doesn't help that Morgan is a very passive baby either. Right now, when she get frustrated with something, she'll cry for a little bit, then she just gives up. I was given some basic exercises to do with Morgan to help, but we will also be going to physical therapy once a week. I did ask the therapist if this delay was something that would eventually fix itself. It will, however not necessarily in the correct way. So Morgan may learn to sit up on her own, but she may not learn using the correct muscles. If she were to continue this incorrect behavior, it could be much harder and more painful to correct later.