I think you're right. I'm pretty sure she's just thinking that given enough time everyone will get over it, life will go on, the kids will eventually come around and see her again, she just has to push through, and the sooner she does it, the sooner everyone will get past it. And there is truth to that I suppose.
Actually the thing that has been most interesting is that they've both on their own really rallied around me...not in an adversarial way (choosing me over mom) but more in a compassionate, supportive way which has been surprising and, I have to admit, kind of nice...and also made me feel like I/we have done some things right with them.
Was hard to see any positives here at first, but that's definitely one of them.
And of course the way the feel is that they want their intact family back as well.