Hi, if she lets you scratch her neck, that is a really good progress and I believe not all the budgies let you do so no matter how long you have the budgie and tame them. My Cloud lets me scratch his neck and head, only when he wants me to. He makes it very obvious by tilting his head to the side, opens his neck and fluffs up his head feathers when I put my finger close to his cheeks. If he does not want it, then he backs off. I think this does not mean he does not like me. He just do not want to be touched all the time, which is understandable. He also chirps every time I come back from work and sits on my finger and chatters for long periods of time when I talk or sing to him. You could also play music for your budgie and may even sing to her if you like singing. It is always good to talk to your budgie every time you walk by its cage, so she does not feel ignored. It takes time and patience to build trust. But budgies have different personalities like people, not every single one of them will act exactly the same. Some might like human interaction more than others and I think this does not mean they do not like/not trust you.
Thanks! Yeah she definitely fluffs up and tilts her head when I scratch her and she seems to enjoy it but it takes encouragement as she isn't sure when I first go near her.
She does chirp when we come home and she screeches when we leave the room!!