Well, the popular use of the word does point to an unbalanced female. Given that you have posted in HG, I doubt that is what you are looking for. There really is such a thing as a Bunny Boiler. Arrow Stove (UK) chose the Bunny name for one of its models. I can't remember the details as I only noticed because it was funny (although I was actually thinking of Yosemite Sam brewing up some hasenpfeffer). If you google for 'arrow stove' and 'bunny' I think you may find what you are looking for.
That is pretty funny. A bunny boiler is a woman who is dangerously obsessive with a man. See the movie Fatal Attraction for that bunny scene.
A mad obsessive woman who wants to control her partners every move and know everything he does. The term comes from Fatal attraction where Glen Close has an affair with Michael Douglas then after he breaks up with her she tries suicide, killing and putting his daughters white bunny in a saucepan of water on the stove in some weird attempt to draw him back or get retribution if he doesn't. In the UK its also used as a slang term for a girl who wants loads of kids and to settle down very quickly early on in a relationship.
