It's in German and she still calls him 'sweetheart' after the second it. I try to translate what she says.
"Kurt, I know you're still angry at mommy. But you know why you need to stay here."
"It's not so nice what you've done with Sarah and that's why you need to apologize to her."
"Sweetheart, is everything alright?"
"Kurt, look at me."
"Kurt, what's wrong?"
-kid stands up-
after second hit:
"sweetheart...."
German is not my mother-tongue for it is Dutch, but this is what the woman said..
You almost got it right. She says:
Kurt, you are probably angry with mommy now, but you know why you had to go upstairs.
The rest is a perfect translation!