Hey ShellBell,
Lord! That would drive me nuts! I'm a freak about being on time now that I'm an adult! I hope my boys wait a while before hitting that speed bump!
...My kids are super little, so I am responding more on my own personal experience than as experience as a parent so take it with a grain of salt;
I was diagnosed as attention deficient when I was 12. I had the EXACT same problems your daughter is having. I was late all the time, I forgot things constantly - mostly because I couldn't pay close enough attention to collect the important details it took to recall what I was supposed to - I forgot homework, tests, chores, plans and even friend's parties. I was always daydreaming, and (I see you're from NC so you'll understand the term) lollygagging. I just sort of meandered through my day.
My parents were so frustrated that they asks our Dr about it because as a result of all of this, we fought like crazy. They would get mad at me, I'd get mad back, not realizing the whole situation of course. They'd yell, I'd get defensive and yell back, not understanding why everyone was so angry!
Turns out I had attention deficit disorder (I HATE the abbreviation because I don't feel its taken very seriously anymore) and I literally *couldn't* focus on my tasks in order to be on time, remember homework and tests, remember to go to a practice or rehearsal, etc....
I was on medication for about 4 years, but I hated it. I took myself off of Concerta when I was 16 because I wanted to learn to deal with it on my own. I have since learned how to manage on my own, but I do still have trouble with "rabbit trails" as I like to call them.
The silver lining here is that I am the only person I know that can actually do 15 different things at one time. Ha!
...Perhaps she needs an evaluation? Please don't take offense! I'm sure there's nothing "wrong" with her, I'm just saying maybe you're asking her to do things she really cannot do at this point in time.
There are a lot of other means of taming down attention deficit disorder, including a diet change, natural remedies and herbal supplements - so don't flip out about the possibility of medication. Although, I will say that when I was on the medication I did really well in school and didn't have any more trouble with forgetting or daydreaming... I stopped taking it by choice, and you guys can always take her off of it when you think she's ready to try something else and her grades are safe enough not to suffer if he hits a few bumps in the road along the way.
I hope this helped a little. Try not to get angry with her. I'm sure its not easy, but I bet if you talked to someone you could get to the bottom of it and safely navigate your way through her teen years!
Good luck!