This is even more absurd than Peter Parker getting bitten by a radioactive spider.
Spider genetic material incorporating into human DNA and resulting in phenotype changes isn't particularly realistic, but there is enough precedent of real-life GMO for the layman to suspend belief.
In contrast, everyone has heard from Buzzfeed, Reddit, etc at some point in their life that the "we use 10% of our brain" thing is completely false. It's like making a movie on the premise of the world being flat.
The writers know better, it's just a blatant insult to the audiences intelligence.
The premise would be lot better if it was some kinda DARPA designed human-computer interface implant gone wrong. It be more topical and we'd get to see her fighting the military instead of a bunch of Asian Yakuzu looking Johnny Mnemonic rejects.