You question really intrigued me so I had to look it up. I had in fact never heard of her, but I love these old stories of gore and torture!! In my opinion after reading the story, inbreeding was very common in those days. So was insanity due to this very reason. That is why a lot of the Roman emperors were crazy.
You think just kind of sick minded? Do we really need to ask if she was crazy? Inbreeding is a likely factor, but who really cares why she was so crazy. Plain and simple she was an evil, crazy woman that killed a lot of virgins and bathed in their blood. By the way, it was not just the blood of a girl that she thought would keep her young, it was the blood of a virgin. There was still a lot of superstition during that period.
I believed that she in fact did have a mental illness. But also, with inbreeding being a key factor, the entertainment of the time was also gory. People were tortured a lot back then, one of the methods being to cut off the stomach of a horse and to sew it onto a human and watch the human struggle when it was done. Elizabeth grew up watching things of this sort and it must have messed her up. Added with inbreeding, and she became a crazy psycho killer. The problem is, her killings would've been stopped. Her family, one of the wealthiest at the time knew all about her murders and many of the towns people. But no one did anything. Her family would lie for her and people would not come forward and tell because they were afraid of what her family would do. It wasnt until she ran out of peasants and she started to kill the girls of nobility that something was finally done.
Well, I don't think so. I think she was just evil. Plain and simple