Look at her diet firstly - seed based is a no-no. Her diet should be mostly vegetables, if you're on fb parrot pantry etc is a good help. You can bake them healthy birdie bread. :)
You can feed a "complete" food like harrisons pellets - if she's on seed you will need to convert her. I find crushing the pellets/putting them in blender then adding water so it's a mash and serving warm helps. Or you could just add water and it will soak up. To help the initial flavour you could add a bit of pure orange juice/peanut butter/something nice and gradually reduce the amount of flavour.
Often a parrots food is far too high energy and this causes health problems. Liver disease, hormonal problems... a better diet will show in your birds behaviour. :)
Worth taking her to an avian vet for bloods and poop check.
Something that really helps with biting is training and you yourself learning her body language. The training just means you can ask her to do things you want her to do - and also if positively reinforced makes her more inclined to do these things.
Look up clicker training parrots. It really helped my bad tempered conure, it opens communication. :) Makes out of cage time more manageable - and as a consequence more out of cage time!
Something to address is that most parrots will pair bond with their favourite human - so they actually see them as a mate. It get's worse around breeding times. It can cause behavioural issues such as jealousy, biting anyone that comes near their preferred person or that person themselves. They can become very unhappy and scream (abnormally - some loud noises are expected), pluck feathers or even self mutilate... it's best to discourage this by limiting all scratching to the head. :)
Theres loads of good parrot groups you can join. It's hard getting it all down here! Start with a happy, healthy parrot - then training should make a difference.
It's worth noting that as we can't read parrots as well as parrots can... we WILL be bitten occasionally! It gets better with time but it's always there. :)