My 5 yo is late for almost everything. Sometimes it is her fault. Sometimes it is mine. Mostly her though.
For example, she has just arrived late at the school disco. This is for a number of reasons. She had a tantrum in the shop, on the way home from school, because I wouldn't let her buy some balloons. This meant she was late home to get changed.
When she did get home, she decided she did not want to wear what I had chosen, as all of her friends were wearing dresses. So we had to find something else.
She then lost the purse I had given her two seconds before. And finally, just as we were about to leave the house, dd2 declared that she needed to poo. I don't think any of that was my fault.
Reasons for her being late for school on occassion are usually remembering she needs some thing for a project, as we are leaving the house. Putting her packed lunch down and forgetting where she has put it. Deciding she needs loo on the way out of the door, refusing to eat breakfast, losing bits of uniform I have just placed in her hands seconds ago.
I'd love to be able to supervise every move she makes on a morning, but I can't. I usually do mornings on my own and I have dd2 to feed and dress also. And the dog and cat need feeding. Dd1 is impossibly slow at everything she does.