Source: Black Sabbath (not the rock group)
Location: In her house
Threat Assessment: 2. If you don't screw with her. If you aren't in her house. You'll be fine. If you break rule one and rule two you will mosts probably die. She can play all sorts of tricks with water and light. Then she can come floating down after you and scare you to death.
Limitations: Seems content where she is.
Personal note: This scared the poopoo out of me as a kid.