I didn't put it in those terms to D11. I'm not even sure how it came up. She was asking questions and I told her "I still love the STBXW I married. I don't really know the person she is now."
CTH, don't do that to your kids! Say "part of me will always love mommy, she gave me you!" That's all you need to say, you don't need to give the impression that there is something wrong with STBX although there very well might be! Be careful, the kids love both of you and that's for the best.