Book Spoilers:
Spoiler:
I am not sure why they are afraid of her in the movie except that she is evil so she is willing to go further than they are and old so she has more experience. In the book they go to the site that the Overlook was on not to use it against Rose but because that is where the Knot decided to camp out, partly because the evil that happened there draws them. Danny and Abra are not hiding but going on the offensive because they know that they have to end it. They should be more afraid in the book because there is more than Rose left for the final fight.