Or, if she isn't a lich have her die and resurrect her in a church in deyja where she will become a zombie. Then let your entire party die (PUT MONEY IN THE BANK SO YOU DON'T LOSE IT!!!!!). There's a glitch where your character will constantly be a zombie and can't revert to the old voice/face model (maybe it isn't a glitch though because they get facial expressions for insanity, disease, etc....)
Hope that helps.