Your response is simple: "Look, you decided to get a new place and you will have to be a big girl now and figure out how to handle the expense of living on your own. I didn't make you move out. I didn't decide for you to get a new place. You made all those decisions on your own without me and you assumed that you can just demand for me to finance your new life, and you need to know that I won't be doing that for you. Since you made all those decisions, you now have to figure out how to live on your own without my help since you offered the same option to me. FYI - from now on, I will take care of myself and my children when they're with me and you will have to learn to do the same at your end when you have them. You chose all of this, now deal with the consequences."
Where's the "STANDING FREAKING OVATION" emoticon???