ITA w/ Geofizz RE training to use the planner. Our elementary starts 1st graders on the planner with group copying at the beginning of the day but progresses as the child gets older. By 5th grade, the students know to copy down information conveyed orally during the middle and/or end of each class in a fluid way. Some kids catch on slower and less efficiently but surprisingly except for the ones who are clinical, they do given practice.
Your DD really doesn't appear to have a disability, although she may be on the lower end of normal. DS12 is in that category as well and I did let him suffer the consequences quite a few times starting late 4th grade. Prior to that, he had his twin as a crutch but there came a point when I felt the scale tipped where he would benefit more from failing than enabling. Of course, this only works if your DD cares about her grades and reputation and buys in to the concept of personal responsibility. DS still has occasional lapses, but so do most other 7th graders. The good news is that your DD will learn and will be ready in future years when more and more teachers will operate this way to some degree. Except for the chaotic description, everything else you mentioned are typical in high school classrooms and many middle school classrooms as well.
Your DD has to develop a new routine, particularly for this class, and she probably will just from being in the class week after week. With my oldest, who had an IEP with multiiple diagnoses, routine and clear labels help. For example, the left side folder pocket has a huge label in red that indicates "HW/CW: Must Turn In" while the front of the folder/binder lists steps for the beginnning and end of class, such as EMPTY Turn In pocket & check planner. Regarding the "turn in as you leave" assignment, it may help if your DD completes it ASAP and then place it on the same corner of her desk where nothing else goes. Again, automaticity requires time and practice to develop but if she establishes and sticks to the same routine, it will develop faster. Regarding parent info sheets and forms that get forgotten, my kids (and all their classmates) are provided a special folder, which is placed next to their planner (at the top of the required huge binder) where all such papers go. Again, it may take 6th graders a few weeks to get the hang of the system but it does help both students and parents to have one place to look. Of course, the students have to comply and put all such papers in that special folder, but it looks like something that your DD can get use to doing.
Good luck, it's not easy but achievable with time and practice. I also would not ever expect perfect results even if it does come naturally to some kids - DS still messes up now and again but it's recoverable when it's the exception rather than the norm. While he is still really spacey in general, he has an incentive (A's) to succeed in school and developed a system that works for him there.
