I really enjoyed reading 'The Last Lecture' by Randy Pausch. One of my favorite parts is where he actually breaks down the skills needed to work well on group projects, and explisitly explains how he teaches - and provides feedback - on these important life skill. Knute, if you haven't read this book, it's worth getting a hold of and doing a quick read. It won't answer your problem, but might give you a larger perspective on it.
As far as 'How do I parent my child so she'll be less like she is and more like I want her to be?' I can strongly recommend:
Transforming the Difficult Child Workbook: An Interactive Guide to The Nurtured Heart Approach [Perfect Paperback]
Lisa Bravo and Howard Glass.
This book is so poorly named, and yet it is full of great suggestions as to how to change someone. Before I read this book I wasn't even really sure that my job was to change my kid! Do I think that by calling attention to what your daughter is doing right you can 'make' her more the way you think she should be? I sure do!
I would get out my magnifing glass and look for (or create) instances when your daughter is being appropriatly assertive and praise, praise, praise. It isn't fast, but it works.
Love and MOre Love,
Grinity
