If this is a reply to interrogatories or a Notice to Produce in some state Family Court where you are not represented by counsel, then I would present the emails verbatim in any order you like, as long as you leave none out. In this context it isn't your obligation to establish the authenticity of the emails, other than by your swearing, by certifying the responses, that the information you are submitting is true. At some point your adversary may want to argue that they are inaccurate or incomplete, and I would imagine that your state's discovery process allows you to ask the other side to admit to the authenticity of the emails, or to produce any evidence they may have that the emails are false. I'm sure you also have the right to ask that the other side (or any other recipients or authors of any of the emails in the thread) produce any emails that they may have.
I really hope that this issue turns out the be the most difficult one you have to face during this proceeding.
For right now, just put the emails in chronological order, oldest first, as that is the natural way to read them. You ought to preserve the original emails on your hard drive if you can, just in case there is an evidentiary issue that is important enough to warrant somebody hiring an expert.
I also have to add that I would strongly agree with the poster who suggested you follow your lawyer's advice, but I'm guessing you must be representing yourself, that you're aware of the benefits of being represented by competent counsel, and have made an informed decision.