You are probably reading too much into it, maybe your daughter in law was just happy rather than gleeful, and surely there is no reason why they can’t spend the weekend with friends.
I know it can be tough when you’re so far away, but you have to make the best of it, don’t let them see you’re put out about it, that could very well have the opposite affect, and annoy them
“We start school too early in the UK!”
