Bird Cockatiel help! Dont Ignore try to awnser!?

Hello , i have a bird named Kothy, and she is adicted to Mirrors. She use to be out of the cage in my shoulder all the time and now , shes in her cage looking at her self 24 .7!! Why does she do this? Ohh and one other thing. wen she is near Blankets she like to make her little Nest and sitts there for a wile. What does this meen?