Hi – I'm a n00b on this forum, so forgive me if I'm digging up ancient history.
Allowing your grey to sit on your head is not a good idea. In the parrot mind, altitude is power!
I have 3 of the little monst… errr… darlings

and they aren't always as harmonious as we would like them to be and they bicker from time to time. An altercation usually starts of with them trying to climb higher up the day stand than the competition. If you are higher, then you are in charge! It's the same with people. As a rule, when I'm trying to gain the trust of a nervous bird, I ensure that my eye level is the same as the bird's. That way, there is no sense of dominance. But when I'm disciplining a naughty bird, I always make sure that my eye level is higher than the birds.
But this is all about flying…
Now you're going to have to forgive me here, but I'm rabidly anti-clipping! Even you are are going to clip your bird, you shouldn't clip a bird younger than 18 months or so as it will hinder the development of the chest muscles. But as your litte TAG is only a baby, I'm asuming that she was clipped when you got her (in which case I'll get angry at the breeder/store you got her from and not at you

).
But here's a novel approach to your problem: make sure that her immediate environment is safe so that she can't hurt herself – net curtains on the windows and flyscreens on the doors, for example – and
then harness train her! When next she moults, don't clip her again. I have written a series of articles about harness training greys
that can be found here.
Here's our 17-year old CAG hen,
Ndhlovu doing what she loves most of all – flying!



The rewards of having a fully-flighted, harness-trained grey are unbelievable! The thrill of seeing Ndhlovu in the air is indescribable (which is why is am struggling to put it into words

)
Give it a try!