It's not bad. It's not really empathizing, though. And mind you, I completely understand that she wasn't exactly empathetic about how you might have felt to the bombshell with her parents. So come here for your empathy...
How about:
"Yes, it's definitely been a stressful week. I'm happy to take the kids. When you get some time - probably won't be more than 15 minutes - is is possible to call me so we can plan our time with the kids? They're in the middle of this, and I want to make sure that they have time with both of us because they need that. I'll do whatever I can to help."
Stress the importance of the kids. And if she's not agreeing to do this with you under this pretext, well, then you've got some bigger issues looming and you can come here to get more specific feedback.
Make sense?
"There are only 2 ways to live your life. One is as though nothing is a miracle. The other is as though everything is a miracle."
