Celeb, I take it that you're speaking out of your hurt and anger. (((HUGS))) I hope ED will understand that if she reads this page.
I agree that COing a whole family is "extreme." But what I'm wondering is what does it mean? Could mean a couple of things, I think. For one, it could mean that she is being controlled by SIL, as JSB talked about. But if you think that's the case (I'm not sure if you do, but you referenced JSB, so maybe), it's not really her fault and no anger should be directed at her. I may not know the full story, but wouldn't it be better to just let her know that you still love her and are there for her and the kids if ever she's ready to reconnect?
Another possibility I've read on MN and elsewhere is that some people CO those who defend others that they've CO or try to get them to change their minds. So, for example, the godparents kept trying to persuade her to reconnect with you, then she might CO them. Then if, say, an aunt stepped in on behalf of you and the godparents, she might CO the aunt. And so on. So, in that case, it's not so extreme. Or the extreme thing would be one person after another getting after her, even having seen the pattern. Also, IF this is what happened, then while these people meant well, they were just irritating/aggravating her and I can sort of see her pushing them away. Saying things that upset her more won't change that.
And it certainly won't help the kids if you're concerned about them. If you feel the kids need to be reunited with you and the extended family, then first the adult relationships need to be repaired. It's just not going to happen without that.
Is there a clue in what ED said in the support group as to why she distanced you and how you could begin to heal the rift?
But you say that's no longer possible, and I understand (that is, if this CO was truly ED's choice). But then, well, what can I say?...