Hi!
I had a very similar experience with my cockatiel. She was hand-reared, but was not handled for a couple of months and had become quite afraid of hands as her breeder mishandled her instead of asking her to step-up onto his finger. You can read my little story
here if you are interested!
Do you have a play stand? It is very important for your birdie to know that it is safe both in and out of its cage. This sense of security will greatly improve your bond with your cockatiel, as she will know that your space (i.e. out of the cage) is also her space. Try to coax her out when she is a bit more settled, but do not chase her or force her to come out. You can put the play stand nearby with lots of toys to attract her to leave the cage. However, I think you shouldn't do this too soon, as you don't want her to get stressed easily. At the right time though, this will be a good option.
You are on the right track hand-feeding her - really, this will just take a lot of patience. It took about a month for my baby to feel comfortable around me, and it really depends on the individual bird. You can start to vocalise "step-up" every time your bird puts a foot on your hand to eat, which will begin the process of teaching your bird how to step onto your finger.
Here are some general steps you can follow to familiarise your bird with your hand and voice:
1) You could spend about 2 weeks sitting next to or near the cage talking to her for about 1 hour a day, and if you can, even longer. You can keep the cage door open. You can talk about anything really - it will help for her to adjust to the sound of your voice. Keep your tone friendly and upbeat - parrots love animated emotions - just don't be so enthusiastic that you scare them.
2) After this period, I recommend familiarising your bird with the idea of your hand OUTSIDE the cage. Touch and hold your hand on the left side of the cage for a few minutes every day for a week, and then repeat this process for the right, front, back and top of the cage (so right side for a week, top for a week, etc).. See why this will take a lot of patience and time.
3) Next, you should be able to familiarise your bird with your hand INSIDE the cage. Similar to the above, you can start by placing your hand on the left side of the inside of the cage for a few minutes every day for a week, and then repeat the process with the right, front, back and top of the cage. Your bird may at first shy away from you, but as she realises that your hand is non-threatening through this repetition, she will become less afraid of you.
4) Once your bird appears fairly comfortable with your hand in and out of the cage, you can offer them seed, millet, spinach, apple or any other treat/food that they like using your hand, like you have been doing. This is a great step. food=trust, and it is very important for you to let your bird know that they can trust you in this way.
The hope is that your bird will eventually feel comfortable enough to actually step onto your hand and eat seed and/or other food from your hand. This, coupled with a smooth transition into out of cage time, will help to strengthen your trust bond. This takes a lot of patience - every bird is different. It could take only a few weeks, or a couple of months - persist and persevere though! It will be so worth it in the end. As I said, I relate - Berry was timid and afraid, and now she loves cuddles and scratches far more than my other two birds who I never had to tame!
Good luck, feel free to update us or ask any other questions!
