I thought there was a point where the school has to report unexplained absences or very frequent absences.

If 4 kids from the one family ranging from year 3 to 11 are away regularly once or twice a week for no reason surely that rings alarm bells?

It's a matter of "we slept in" and then the mother is refusing to drive the kids to school late.

It's getting beyond a joke or should I just stay out of it?

It's DH sister I'm talking about. Can't believe she's now trying for a 6th