Legal Question in Intellectual Property in Florida

You should obtain a written waiver from the ex before you make any references about her. If any references you make to her result in her being identifiable from those references, she could have an actionable case against you for Misappropriation of her Persona. The value of that misappropriation, and even the extent to which your references to her make her identifiable would determine the value of any case or claim she could launch against you, but you can be assured that if the book is successful, the lawsuit will come.

Additionally, emails that she wrote and sent you, once duplicated and republished as part of your manuscript could very easily open you up to a Copyright Infringement suit. I seriously doubt that she has registered the copyrights she has in the text that she has written, but if she wrote it, it is protected under the Copyright Laws and should not be copied and reproduced without her written consent.

I suspect that there are a few other issues of concern with this project than you have yet to consider. You should discuss this project with an Attorney who is familiar with these issues, and have him/her review your document before publishing. At the very minimum, you should obtain releases from the ex concerning the use of her name (or even vague description), and definitely for the use of text that she authored.