As long as the kids are not medically malnourished, there's really nothing "illegal" about what Mom is doing. She can indeed turn up at school for lunch and take them to McDonald's - even on your days.
You said yourself that you're at work; your parenting time is not really being interrupted.
I'm not sure this is the hill I'd want to die on. And comparing it to hanging with the kids' grandparents isn't quite the same thing.![]()

