User blog comment:Martialmaniac/Zodiacs Nen Abilities - Geru/@comment-4637768-20160102212607/@comment-5780397-20160103004101

I wonder if she needs Manipulation since it's her own arm, but you may be right.

She is a Zodiac, it wouldn't be surprising if she were more skilled than Killua, but poison is an object with a mass, not an abstract quality, so it's conjured out of one's aura, not transmuted.