OK don't panic but you do need to stop her biting and you will only do that by withdrawing shoulder privileges and setting some boundaries. She sounds hormonal and at a year old this may well have hit her like a sledgehammer since it's the first time she will have experienced it. She doesn't know what she is doing so you have to take some control until she gets over it.
When Syd was like this I suffered some severe bites so you mustn't make yourself available to get bitten. I covered up with gloves, long sleeves, a hoodie, a hat and scarf glasses etc. More than that your little one has got used to perching on you and you need to let her realise that that is not a right but a privilege that she earns with good behaviour.
So try your level best not to get bitten to start with. Watch her body language carefully and use a piece of perch or something for her to step up on. Stop her getting on your shoulder and put her away somewhere neutral - not her cage - maybe the back of a chair or something and ignore her completely for a few minutes. If she was in a flock other birds would banish her if she misbehaved so you have to do the same.
Some recommend no reaction to a bite, keep calm and put her away from you, I have found that if I squeal that I am hurt Syd understands better. She will return to you with a little more respect, but expect to repeat this process multiple times and not just with bloody bites but any bite that is harder than you want. It will take time, protect yourself.
There are other things that may spark her off. She may be getting it in her head that you are her property and be jealous. She may think that your relationship is more than parent/child which is what she needs to understand. Don't pet her anywhere except her head - treat her like a toddler child and she will learn the boundaries. She is growing from a cuddly baby to an adult with the mind of a toddler.
It will be a couple of weeks or more before she pulls out of this so be patient and kind but firm and before long she will return to normal but with a little more respect. This will be the worst hormonal situation because it's the first.
By the way - welcome to the forum - there are some very experienced folk here who will help more but I hope this gets you started.
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PS there are a lot of threads with this problem so read and read - at the bottom of my screen some are listed, have a look.
