I have taught elementary and was the 504 Liasion in the school.
A 504 plan is a document that guarantees that your daughter gets some accomodations and modifications that she needs, but IS NOT considered special education.
An IEP is the official document for special ed. It requires testing and qualifing. Federal money is spent to help the child with interventions (one-on-one therapy, help, etc), time spent in a resource room, and individualized support.
A 504 plan is a document created to support your child's right to education. If a person has an official diagnosis from a doctor that prohibits him/her from learning, the document is written to protect him/her. For instance. If a student has a broken leg and needs extra time to get between classes, the document protects the student's rights from being penalized for tardies, or points taken off for being tardy, etc.
Simply put, it is "common sense on paper" for your daughter. The things you mentioned that you did before would be things you would put on this document.
Imagine a teacher that isn't understanding of a student's unseen diagnosis of ADD. The student cannot stay organized and needs his backpack with him to stay organized. The 504 plan would list this. The student cannot be penalized for having his backpack if the school rule is NO backpacks in the classroom (often a rule in some schools).
Schools are required to start the process within 30 days once a parent or teacher mentions wanting a plan.
I would highly suggest you go through with the plan. It will allow you to list the things that the school can do for you that doesn't actually require money (no extra staff help) and PROTECT your daughter, especially as she enters middle school.
A plan is good for one year at a time and can be revamped as often as possible.
Again, the plan can only list things that do not cost money or extra time from the teacher. (Sitting close to the teacher, allowing more time for assignments or tests (not standardized testing from the state), extra peer help, a specialized homework journal, etc.).
Please let me know if I confused you or if you have more questions! I'm on pain meds now and am struggling to concentrate! Lol.