I had typed up a response to NSM's email and had dh read it to get his thoughts. In talking with him, I've decided that I'm not going to respond. Dh thinks that a) I shouldn't justify her ridiculous comments with a valid response and b) that the best response is to just go on and live my life well and to hell with NSM and NF. I asked dh, "So you're saying I should just not respond then? No emails, no phone calls, etc.? But then what if they continue calling here?" Dh says that I should just either not respond/answer or if I do answer the phone one time and NSM says something like, "Why aren't you talking to me/us?" to just tell her the truth - because I don't have time for ridiculous accusations and pissing contests over whose pain is the worst, etc. and that since that's all they seem willing to offer me, that I've decided to move on without them.
As is often the case, dh made a lot of sense. Sending a response would also serve only to perpetuate the drama and who needs more of that? So I think I'm going to take dh's advice and just move on without them and not respond.
I have to say, I feel a huge weight has been lifted already. Considering how much I improved just cutting NM, NSJ and NHS and all their toxicity out of my life, I can't imagine what heights I can soar to without NF and NSM's toxicity hanging over my head!