There are many reasons that people get divorces. A divorce to remove yourself from an abusive situation is a horse of a different color. If two people have simply grown in different directions and are no longer a match, maintaining contact is reasonable.
A woman separating herself from an irrational, narcissistic (sp?) man can not and should not maintain that kind of relationship. People who have never experienced this tend to think that something could be fixed. For example, by going to mediation. That would be true, if both sides were rational people.
IMO mediation would be a horrible idea for Elaine. It is not surprising MR suggested it. Mediation would be one more venue to rant about her and how miserable she has made his life. One more way to drag her into a controlling situation.
Allowing the boys to form their own family with MR if they chose, is only right. But she has good reason to keep distance.
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JMOO