Note for ROGUES attempting this - I tried soloing her many times as a 25 and 26 rogue.  I could stealth back to her cave easily but her frost nova and slow spells + her lightning killed me every time.  (Note her version of 'slow' reduces movement to 0%!!).  I was finally able to down her at 26 with *Mind-numbing* poison on both weapons.  This is *essential* to slow her casting enough to get next to her / have enough energy to get in a kick and dispel her magic.  Normal casting time is like 1.5 sec or something and those spells hit for about 150-250 each.  Its possible, but you have to be careful!
Gl all