When she's 18, we can do what we want and they would never need to know. Until then - as unfair as it may seem - they have the right to intervene as they see fit.
They have the capacity; no one has the moral right to deny a child, or anyone, the exercise of their own agency.
But, they do have that capacity.
Conversely, if you're in the US, you can appoint her to make medical decisions for you if you are ever incapacitated and list her on your allowed visitation directives without having to contact her or consult anyone else. Just so you know. ;)
I apologize if my negativity has negatively impacted any of you in the meantime.
Frankly, if you were to get run over by a bus tomorrow, it would affect absolutely no one here, positively or negatively. We feel for you, we hope for you, we wish better for you than you've gotten and sort of admire the degree to which you've been able to grow beyond the people and circumstances around you... but we are neither financially dependent on you nor a conjoined twin dependent on your part of the body for basic survival, and we are likely mostly not in gun range.
There is literally nothing you can do which could negatively impact us. Don't worry about it. Best of luck.