They won't say anything because they've seen her anger and they walk on eggshells around her.
Oh, that stinks also. My stepchildren were parentified (that means they were in a home where they had to be the adults b/c the adults were either acting like children or not home) - they were watching their baby brothers since they were 8, cooking, cleaning, changing diapers, feeding them, etc.
When they came to live with H and I, it was very hard for DSD16 to let go of the CONTROL she felt she needs to have. With this crisis, she's trying again to control everyone, and it's so hard to see how the children react. It's so hard to just let it be - they're older now, so they can choose the R they will or will not have with H.
How do you feel about your children walking on eggshells? Maybe it's time they said something if it would clear the air?
I know that H wasn't going to come to DSD's sweet sixteen and I said nothing. Finally, I had had enough and said something to him about how she was feeling, which prompted him to say he'd be there for her, but then he wound up leaving anyway when her friends didn't show up... just the time when she really needed him the most.
Not giving advice, just showing you some situations and how they've panned out, I guess.