Indian ring neck won't adjust to us

Good morning everyone hope your all well

I'm seeking advice on our female Indian ring neck parrot

We got her in January off a family member who purchased her from a pet store
His other animals was causing her distress so we decided to help by bringing her into our home
There is more space in our home
And there are no other animals to make her feel uneasy

But we didn't know what to expect so we had to self teach our selfs on how to care for her and also to make her feel she can trust us
At first we knew things would be very unsettling for her and she would be scared
We have done everything possible that we can think of to get close to her and to help train her come away from. Her perch
She as a cage but we don't believe in locking her away so she is free to roam and fly
But she doesn't she sits on the top of her perch on the cage if we go near her she will fly over to the curtain rail till we move away from her cage/perch
She is still scared of us she won't allow us near to her to even try wash her so we made a bath to fit on to her cage
We know some parrots just don't take to their owners but we are at a loss on what else to try we want to see her roam and flying around the home
We can have doors and windows open she won't even attempt to fly off she is so chilled
She hardly ever makes any noises
I'm so worried that maybe we are adding to her distress because she just cannot trust us

Thank you in advance for any advice
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