Their kids are always sick because apart from Day Care and School they are never around other kids so their immunity is not great. After such long Christmas school holidays, first day back at school and Miller has picked up the stomach bug that is going around.
She wants her kids to live in the bubble she has built for the whole family.
I wanted to say well sucked in then Princess looks like you will be cleaing up vomit today, but NO, it will be Kurt as always.
Imagine if Kurt gets sick, she will be like 'Can't you just look after the kids for an hour because I need ME time'.