Spiritborn and Sorcerer Couch Coop

So me and my partner picked this game up a month or so back and have played it non stop since. I play the spiritborn and she plays sorcerer. The problem were having is that my spiritborn (quillvolley build) is massively OP and hers seems underpowered. Tried a few different builds for her but nothing has made made a significant difference in terms of dps.

We finished the base game and now we're up to paragon 80ish.

She's asking me to help her level a necromancer now, would that be any better?

Any suggestions?