It's difficult, but possible. She's kept alive by magic, which is centered around the organs in her canopic jars: Heart, lungs, stomach, intestines, and brain. If one of them is destroyed, she dies. She can also be dismembered, but that won't kill her, and as I said, she can reattach her limbs. Also, most of her blood has been replaced with salt. She can feel pain too, but not nearly as much as most people. The most she ever feels is kind of a dull stabbing, like getting poked really hard with a somewhat pointy stick.