|Message:||Part of the problem may be that she's becoming an adult, and her hormones are raging out of control; nandays usually mature somewhere around three.
It's not unusual, either, for a nanday to take a while to become accustomed to new toys, especially if they have been abused or neglected. If she bites, try tapping her beak and saying, "No" loudly (this is more or less what another bird might do if annoyed at her). Be prepared, too, to give her a time out by putting her in her cage for a while.
You might also try training her to step up on a stick or your hand on command. Do this training in a quiet room, several times a day, and you should see results within a few weeks. Not only is this training very useful for retrieving her if she ends up in a hard to reach place, but it will help her understand that you are dominant.
You probably will get bitten; with one of my birds, there was a period of about two years when one of my fingers always had scar tissue. But you can cut down on the blood shed by watching your bird carefully and learning the signs that she is about to bite.
Above all, try to be move slowly around her and, under ordinary circumstances, talk quietly. An abused bird can take several years to recover, and some never do altogether, so be patient and appreciate her for what she is; even an abused bird can be an enjoyable companion, and seeing signs of improvement can be a real joy.