i guess i'm a bit late, but i'll write it anyway... i got one-shot by Moder's ice projectile in fully upgraded root armor set + best health food. It was on MP server, 3 players vs Moder so her dmg was increased a little.
Going solo i would never choose root over wolf armor.
If you choose root armor anyway, i suggest you prepare the ground before you summon her. Use hoe and raise a few pillars of ground which you can use as cover when she fires her ice projectiles. Also don't forget frost res. potion and Bonemass power (i did )