All the talk of computers - all Ivy's knowledge is just a huge disk array. Is her CPU strong enough to access/address it? To process it? She stands to become more powerful as her mind grows stronger, and much of magic is will power. Her mind was always somewhat disciplined, but she will get better.
Bear in mind her crude force steel satellites are also defensive - no Fishhead is going to try to grab her without having to dodge a 200mph fire hydrant. Even Blood on His Soul would think twice about grabbing for her and getting hit by an engine block. He may be able to drain magical fire off - what about all that kinetic energy? Didn't work on the big ice cube!
Also - the Denarians may not want to get her to use her knowledge - they may want her to keep her from DISCLOSING knowledge about THEM. We know the Denarians raided and destroy church records - what if some medieval Knight of the Cross discovered Nik can be choked out by the Noose ? He writes it down, Ivy knows it. Even if Nik got the Knights' hard copy, he didn't get Ivy.... i am sure there is more.