I've been reading through these post, and they lack some fundamental principals you should have in your head when taming a bird. I'm currently taming 2 cockateils, a pair of biological brothers that lost their last home for pulling out the female's tail feathers.
For three plus years they lived in a cage and were not handled.
So far, I'm gaining ground, and yes, it's a slow process, it's been a little over a year now.
The first thing I did was whip out a piece of paper, and write down some specific goals I wanted to meet. The main one, which is obvious that you need and want is to:
Get this bird used to human hands. Teach this bird these hands don't harm, but cuddle, love, and yes restrain when necessary.
Since these are bonded brothers I must take them in individual sessions no longer than 20 or thirty minutes.
My birds are now ready to be turned loose i the bird room, but do to reasons for cleanliness I can't allow it until I have flight suits for them. These two are aggressive and will fight with each other.
However, I have gotten them to a point after they are touched initially they don't even try to bite, and yes, they will stay on my shoulder for ten to fifteen minutes unless they get spooked.
Your goals should be short, understandable, with some ideas on how to reach the goal of taming them.
I see 2 goals, possibly three you should shoot for.
1. Gain the birds trust.
2. Convince her that the world is fantastic to be in it and not in her cage all day.
3. Get her used to human hands.
Good luck. This is not an easy task.