Ok excellent start here! I appreciate the help getting a focus on what my concerns are

First to your A-D...yes yes yes! Affirmative on all counts. Our school is not bad, IF you are average AND you are a conforming traditional type learner. I have three very bright older kids and two of them have gotten lost in a system that did not work for them. One has already graduated and is in college, the other one... we are fishing him out just in the nick of time and getting him into a more 'outside the box' school. The middle one just cruises along doing just fine but I have to wonder what it would be like if we had been better advocates for her.
On to my youngest, she is a fun bright happy girl, who is very much a people pleaser, a conformer, and perfectionist. So far school has been a cake walk for her, she often spends time in her day working with some of the lower achievers (which on one hand is healthy and builds her confidence and on the other hand...isn't there something more productive she can be doing?)Her older sibs are 6, 9 & 11 yrs older than her. She is extremely bonded to me although she adores her daddy, she cries if I leave her home sometimes. Socially she is very mature, plays well with others, is very conscientious and academically she is advanced in most of her subjects. She also has some anxiety.
My 'top 3' concerns would be that:
1) I have already (mostly) dropped the ball on her older siblings and let the school lead the way....which lead to two of them having real struggles as I did as a kid. I want to be sure that I am a stronger advocate for her and want to be sure that I really understand what is appropriate for her education so that I am better prepared to do battle as needed.
2) How to encourage her independent thinking. She easily takes the submissive role too often and I want to be sure that she is growing into a strong young lady who is ok with her own identity. I don't want her to get lost in the system.
3) How to meet her needs....letting her take the lead, and not pushing because she is prone to letting others make decisions for her.
I think that is it for now....any advice is greatly appreciated.