In regards to whether or not to send a letter for closure, if she really thinks that sending a letter would be the most helpful, would it be possible for her to write a letter to him, stick it in and addressed and stamped envelope, and then put that in another envelope to mail to the OP, and then the OP can either mail it or toss it or burn it or whatever without Jane knowing the outcome until she's over this? That way she gets the satisfaction of writing and mailing the letter, but if OP destroys it, John never gets the satisfaction of seeing Jane's final hurt over all this.