It's not a huge deal; when I was a teenager I worked out a way to deal with it by asking her to give me a ten minute warning when she was almost ready to go. Otherwise she'd say "We should get ready to go" and I'd put my shoes on and then sit around in my shoes for half an hour while she did one more thing or found her purse or decided spontaneously to clean out her shoe rack.
She's never late for anything; we're very prompt people. She just...fusses a lot before anything happens. Christmas eve, we were putting food out on the table but kept NOT BEING ABLE TO EAT because she had something else to do in the kitchen, which at one point involved arranging the dessert plate. Finally I said, "Do we actually need to do this now? No? Are you hungry? Yes? Then COME EAT SO YOUR CHILDREN CAN EAT."
This morning Mum literally said "We have to be somewhere in two hours. I should start breakfast now." Breakfast was going to be leftover kolaches, but is now leftover kolaches and bacon and eggs and veggie smoothies. I don't know how she manages to take fifteen minutes to make a smoothie but by god she manages it.
I have to remember to be patient when I'm around my parents. They move at about 3/4 the speed I do. I forgot why exactly I hated living with them so much, but Emmy's frustration with their lack of velocity is visible. I love them, we both do, but escaping to the speed of actual life is going to be as much a relief for her as it was for me, I can tell.