Firstly, if she is reading the KJV then you should advise her to get the NIV. She is clearly living in the past. The Dickensian or Shakespearean eras spring to mind.
Next, if you don't believe in scripture why quote it? You must believe in at least some of it (or agree with it at least). You are defeating your own arguments when you quote scripture.
She might be wrong about her interpretation of scripture and yours might be the more accurate but this is where your focus should lie.