I actually think it's brilliant on the part of the writers with her over the years as well as the acting by Melissa McBride. She really knows this character and how to play her.
They play on the fact that Carol lived as a mouse in the first 2 seasons and before the apocalypse. She was scared of her own shadow and has an understanding of how peoples desire to take care of her because she was weak works. She shifts to that persona when needed not only to manipulate people, but to take them off their guard. When she does that nobody realizes she's the most dangerous person in the room and make no mistake, she is.
Through the course of the Walking Dead shows they have made a lot of mistakes with characters, but Carol is their masterpiece.