Best way to do it is if she doesn't spawn or if the caves don't spawn just do the rinse and repeat method until it happens. It's all based on luck. She sometimes won't drop it either. That gets aggravating.
I have to admit, I'm lucky. I literally stumbled upon all three parts of the staff. Now if I could just get the plans to drop...
So far i've only been able to find the Mushroom. Stumbled upon it my first run through on Normal. Where does the Caverns of Frost spawn? Someone said the Gemstone was the only other part you needed.
It spawns in Act 3 The Fields of Slaughter.
Sweet. I'm not too late then on my Nightmare playthrough. :D
Awesome. Good luck my friend, Chiltara (I think that's her name) has a low spawn rate. I'd have been done with Act 3 on Nightmare by now if it wasn't for me spending almost 3 hours trying to get her to spawn and then getting her to drop it.