Sounds like a lost cause.
But she also sounds like she has managed to collect a paycheck for a long time by doing absolutely nothing, which I sort of admire in a way if she's not an absolute burden on the rest of the office.
The troubling thing is that you have become the "catch all" for her questions.
I'd try to figure out a way to direct that toward someone else.
Maybe just a simple "You know what...... Rick in accounting is really good at internet".
The best way to not be the catch-all for someone's stupid questions is to not give a direct answer and force the person to think for herself (or take her questions somewhere else, which is more likely).
Q: "How do I ______?"
A: "What do you think?" Or "I think you know the answer to that."
Do that a few times, and you'll no longer be the go-to.