She can get a subpoena of email and phone records as it would be relevant -- it happened during the marriage and could show dozens of different things. She could also subpoena bank records and anything else of the OP since they are MARRIED and this is a DIVORCE. Hence anything that was part of a marriage (including the individual parties' records) is relevant to the divorce. Look for your email to be subpoenaed and obtained. I take it you were cheating and hence have something to hide which is why you are worried.
Parents should remember 3 things: Love your kids more than you hate your ex; when you have children the relationship with the other parent is until death; your children determine what type of nursing home you end up in.
Nothing stated by me should be taken as giving you legal advice or forming an attorney/client relationship.
Attorney-GAL in Ohio.
I've removed the knife from my back, polished it, and will one day return it -- long after you think I have forgotten.