A lot of people "stop" developing in some way or another when the trauma starts. It's normal for trauma survivors. I too have parts so it is a little different. Most of my friends are trauma survivors too. I now one who is in her 40's and has a pasifier and bottle in her night stand (no parts). If I am working on specific pieces of my history I wet the bed and I have another 30 year old friend that bed wets too.
One of the things I love about my massage T is that she believes everyone has parts! So she totally gets it.