Honey. The only way to win is not to play, right?
Your daughter is addicted to drama and frankly, I’m side-eyeing your sister and cousins who suggested you look at that photo pretty hard. You’ve been doing so well...why go there?
By responding twice, you just affirmed to her that this a great way to kick up a nice, juicy fuss, yes? Yum, she loves that. So you can look forward to more of the same.
What she’s doing to her kids should be criminal, but sadly, it isn’t. IIRC, their actual father is pretty grounded, yes? At least they have him. And to the extent it’s possible to do without involving your toxic daughter in any way, implicitly and quietly let the kids know you’re there for them...birthday emails, online gift certificates, etc.
How about you block her?
Sending you a big fierce hug.