My husband always stalls when it's time to go somewhere. I will remind him the night before what time we need to be somewhere and when it's time to walk out the door to leave he decides he has to go poop or take a shower or do something on the computer or pretty much anything...then we fight because I start freaking out on him...so basically I tell him we have to be someplace an hour before we actually need to be there. Also, you can set all the clocks in the house 10 minutes fast. That doesn't work for us cause he goes by his phone but maybe it would work for you. I would also let her know calmly and kindly that you don't like showing up late to places...that its disrespectful to the people you are meeting and not a good habit to teach the kids, especially when they get older and have jobs.