What about skype? With a web cam, they can also see each other. It's easy to monitor if they keep the conversation on speaker rather than on head phone. They may also appreciate being able to speak confidentially to each other, as they do when they talk with their therapists.
I also have not used "MLC" to describe what H has done to the family and I would prefer to avoid using the term if we connect the kids since it's bound to get back to H. As we all know, one does not tell the WAS that he/she is in MLC and hearing it through the kids will be even less appreciated.
My daughter had only one other friend (boy 12) whose father has done the same thing. They really enjoyed each others company and talked a lot about each of their situations and how they felt about it. This friend has since moved out of state so it would be nice if she could connect with another her age (especially another girl) and they can share feelings, experiences, fears, frustrations, etc.
Our children have been even more traumatized than we have and an outlet with someone that is going/has gone through the same thing could be beneficial.
FYI we are on Pacific time so it would be ideal if we could hook up with someone in our same time zone.