I don't think anyone has said that's a social services call at all. If they did it would not equate to a phone call at all, or even a note on a file. There has to be value to a complaint
Some kids though find travelling tiring, and can't sleep anywhere. Most get up a lot earlier in unfamiliar surroundings, just like adults often do too.
I don't know how many people joke that they genuinely feel they need a holiday after a holiday, or how nice it is to finally come home. Something the girls haven't had, home than straight to school. Everybody is different but it was clear the children were tired out. Just looking at their washed out faces in London was enough for most.