Talk about stress while taking a picture!

So shot a lady for a magazine, at the Science museum, about 30 min before it opened. She had with her child, and was about 10 min late. The exhibit she designed was about children, so we wanted something with the two of them, and tried, then settled on on a stand alone of her. I know we always talk about planning, and to be ready for anything, well, a client 15 min late with a strict 30 min shoot time is something that also needs to be planned for.