I'm answering from the standpoint of one who - back in the days when she was a child and dinosaurs roamed the earth - was so disorganized that she literally forgot about everything, including big projects, and then she and her mother (bless her memory!) had to scramble to get everything done on time. I appreciated my mother's help! I wish my mama had taught me how to focus and organize for myself, but I don't believe she knew how to teach me that. I will say she did the best she knew how!
Does your daughter know how to organize and focus for herself? If she really doesn't know (and many other people besides me don't, no matter how easy it sounds), just letting her figure it out for herself is just like letting her drown and hoping she'll come out of it knowing how to swim.
That's when you step in, if you know how to help her, and guide her baby-step by baby-step. Don't give her a list of things she must do to be organized if she can't handle more than one or two jobs. Let her learn one step at a time. She won't have it worked out in a week or two, but maybe she'll be better and more responsible (and, incidentally, more confident) in, say, a couple of months.
On the other hand, is Daughter being careless? You might *ask* her!
Children seem to appreciate what's fair. So let her have input - don't decide for her. Let's assume she was ill but not seriously ill today. Ask, "Did your brain fall out this afternoon because you didn't feel good, or were you being careless?" She may answer, "Well, I really wasn't thinking about what I needed to bring home, so yes, I was being kinda careless." "Well then, what do you think ought to happen?" "I guess (big sigh) I should miss Fun Friday this time." "All right. I admire your integrity. How about we start working on how you can remember things, and then you'll be in on the next Fun Friday for sure?"
It's worth a try.
When you take over your daughter's mind and heart and manage things completely, that's real fixing, in the negative sense of the word. You're doing the job for her When daughter is just being careless or heedless and letting things slide (perhaps because she expects to be rescued by Mama?), then she needs to find out what happens when she has to take her own responsibility. There are also good places in between those two poles. Your mission is to find out where the right place is.