How long have you had her since you acquired her, maybe the bond has not been established yet? If you had not had her long she may be reacting to the disappearance of yet another owner, with you being gone for 2 weeks. When you first get a grey you should not be gone for any length of time before the trust and bond is set up between you and her. Now that you are home maybe you can get her settled in and then maybe she will stop the plucking. But sometimes once they get started doing it, it is hard to get them to stop, but she may have viewed your being gone for 2 weeks as abandonment by you so you have your work cut out for you.
I see this is your first post, why don't you introduce yourself in the welcome room and tell us a little more about yourself and this grey.