African Grey behavior issues.

I have an African Grey who has never let me pick him/her (we have not had the DNA test) up. I used to be able to pet her (I am going to just us the assumption that it is a her seeing we named her Mrs. Sophia). Now she will not let me do that. She is not starting to scream. So I was wondering seeing that she is like two years old if possible is she going acting out like a teenager does or am I doing something wrong. I spend a lot of time in the room with her and I talk to her all the time. She has a very large vocabulary and even calls each dog by his name when they walk by her cage. Speaking of Cage, her cage is on the large size and I leave the door open a great deal of time for her to walk about it and to go up top to play. I love her very much and want her to be happy so could somebody please let me know is her screaming a sign she is not happy or is there anything I can do with regards to this to teach her not to scream. Secondly how do I work with her on get on my arm and trusting me?
   
Thank you
   
weskilds
   

Correction I said she is not starting to scream and I wanted to say she is now starting to scream. I am not very good at typing or spelling for that matter.. : )

She is reaching sexual maturity, this is the time in the wild that the babies act out a bit, and the parents kick them out. They usually hang around in a large flock for a while (normaly 1-3 years) before picking a mate and settling down. This means that until she is about 5 that she will be using you to learn her boundaries even more than before. So you have to be firm with her, and not let her get away with this biting or screaming. By the sounds of it she is very much loved and is used to lots of attention, so I would suggest leaving the room when she is noisy, and only letting her out/feeding her/going into the room when she is quite.
   
Is she trained to do any tricks? This would help challenge her active mind and hopefully reduce the biting and screaming, while making her bond with you stronger. A few simple things like moving to different perches, playing fetch etc... I like teaching what noise does *blank* make? I usually have a few different animal noises, and the parrot replies with the humanised version, such as woof woof for a dog. It tends to get a few laughs as everyone is expecting to hear a realistic dog bark!
   
Most of all be constant.