TR, I found this one, which seems pretty good - especially to share with a counsellor. Follow the links to read more about primary, secondary and tertiary dissociation.

Structural Dissociation

Let us know what your counsellor thinks of it! I think I am going to ask my new T if I can share the link with her too.

And for the more academically minded... Trauma Information Pages, Articles: Ellert Nijenhuis, et al (2004)