That's a tough one, the oldest. How old is she? Of course it hurts. Bad. It can't not.
With your younger D, I don't know if it's your intent or not, but taking her back when she's mean an disrespectful let's her know that one thing hasn't changed: consequences for unacceptable behavior. And good for you and your son.

They are not all experiencing the same thing, not even the same "facts". They could all be present for the same event in the same room under these (or any) circumstances and each experience something entirely different.

I know it hurts.

My New Year's email to all four of mine was answered by StepD, 33 (as a reply to all) with a curt, "Stop contacting me." StepS, 30, dropped from the radar altogether. So now, in addition to striving to not take it personally, I try to turn it around. "It hurts," becomes a reminder that "StepD hurts; StepS hurts."


Gardener

"My soul, be satisfied with flowers,
With fruit, with weeds even; but gather them
In the one garden you may call your own."
Cyrano deBergerac