First you need to gain her trust. This takes time. She needs to learn that good things come from you. Start with a yummy treat like millet sprays. Get a piece and put it on the palm of your hand and put your hand in the cage. Now, just sit still and wait. She may or may not comeover to your hand to eat the millet. If she doesn’t approach you after about 5 minutes, put the treat in the cage and leave. If she does, then softly praise her while she eats and remember to hold still. If she comes over to bite you, what ever you do, don’t pull your hand away. Try your best to ignore the pain. When you pull your hand away, your teaching the bird that biting you makes you go away, which is what she wants. If you don’t go away, then she’ll stop biting. I don’t recommend wearing gloves. Your bird will get acustomed to the glove and not your hand. Do this every day. One other tip, don’t look her directly in the eye. Budgies are prey for many animals and preditors will often stare down their prey. So you don’t want your bird to think your a preditor. It’s ok to make eye contact, but don’t hold it. Continue doing this everyday. It may take a while for the bird to come to your hand, so be patient. Once the bird is comfortable being on your hand, time to advance to the next step. Cover any mirrors and close any curtains or blinds. It’s best to do this in a small bedroom. Open the door and slowly try to take the bird out. If she hops back in the cage, then try again until she stays on for a few seconds. It’s best to do this when the bird is hungry too so focus on the food. Another way is instead of putting your hand all the way in the cage when you do a lesson, start gradually bringing it further out a little at a time. Once she’s comfortable being a few inches out of the cage, start moving a little further away. Pretty soon, you’ll have yourself a tame bird.
Good luck!