Personally, I would keep the entire floor of her pen covered with pads. That way, she gets used to the feel of the pads under her feet when she eliminates. With time, she will then only want to "go" on what she's used to (called "substrate preference"). Later, you can very gradually decrease the area that's covered with the pads until you're evenually down to one.
Also, I'd ditch the spray! It's obviously not doing what you want it to!
