I'll toss this suggestion into the ring, since bttrfly had a good strategy.

You could always say something like this: "w, if you can't be here by 7:00 AM to do d's hair or bring son his book, then you can meet them at the school yard before they go into the building. Being late is unacceptable and it disrupts the daily routine of getting the children ready for school and out the door."

Sit quietly, the answers will reveal themselves when you least expect them to.
The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.