Can a diary hold up in court as evidence?

Short answer to the banner question is "yes." I have successfully used diaries as evidence in various contexts over the years. Your other questions are more subtle and nuanced -- for example, there are evidence rules saying that if part of a document is offered into evidence, the other side can compel the entirety of the document to be introduced.

But all of that is beyond what is appropriate for discussion in a simple e-mail exchange. You should probably seek consultation with an appropriate family law specialist. I would suggest starting your search with the American Academy of Matrimonial Lawyers, the Nevada chapter of which can be viewed at http://www.aaml.org/go/fellows/fellows-by-state/?showResults=true&state=NV. Good luck.

You should probably seek consultation with an appropriate family law specialist. I would suggest starting your search with the American Academy of Matrimonial Lawyers, which can be viewed at http://www.aaml.org.

If you decide you would like to discuss this with one of the attorneys of this firm, please take a look at our consultation policies, procedures, and costs, at http://www.willicklawgroup.com/consultation_policies.