“I don’t know if this is important, but…”
I can’t speak for anyone else, but my parents dreaded hearing that phrase from me as a teenager. It nearly always meant that I forgotten to tell them about a message or mistake I had made that would have avoided whatever situation we had just found ourselves in.
When it comes to submitting evidence to your attorney, you should take the same approach my parents eventually did—better to know too much than to know too little. You can far more easily discard the excess than desperately try to compensate for being underprepared. It’s a tragedy when your lawyer doesn’t know of a key piece of evidence because you never bothered to mention it to him and ask if it might be useful (or harmful); when in doubt as to whether a fact or piece of evidence might be important, err on the side of telling your lawyer about it and producing it. Hiding it from your lawyer only means your spouse can shank you with it. When it comes to facts in divorce, there’s rarely too much of a good thing.