Heavy, I think the cake eating can apply in your situation as she still wants you to be there to yell or vent at and to take her calls for your kids, while having her separate life. It might not be as cut and dry as other situations, but I do think in applies.
She is calling waaaay too much for the kids and I agree with Kramer that it is a control thing. Maybe talk to your lawyer about it?
I'm so sorry that you are having to deal with this as you don't deserve it. Keep powering through and remind yourself frequently that you are awesome and nothing she does can touch you.
{{{{{Heavy}}}}}
M 46 / H 43 T 24/M 18 S 4 11/6/2014 ILYBNILWY 1/16/2015 Living in separate bedroom 1/8/2016 H moved out