if its park's inner child therapy then having a read through the following descriptive may help...
http://www.ppfoundation.org/pict.aspx
however, it may be a looser term for what your therapist may want to offer you similar to what folks above have described
dollwork can be incredibly powerful through externalising past and or present experiences, relationship dynamics and issues around how you attached to significant people
if you have a traumatic past then it may be helpful to ask your therapist to describe their approaches in detail and what goals these approaches typically have. i believe that clients should be informed customers