I worked as a catering contractor, and her overall attitude was unpleasant. The one occasion that always sticks in my mind was when she found someone had been smoking where they shouldn't have been, and screamed 'whoever it is, I hope they die a very painful death from cancer'.
I hate smoking, but felt that was a little extreme!
She knew she was disliked by family and staff alike, with very few loyal to her - and fully understood that she would be out as soon as Johnny was no more. I suspect that was why she fought so hard to save him, when he had his stroke - but without a doubt, it was her that did so.