Well, unless someone can PROVE the existence of not just one, but TWO SEPARATE Gods, then who's to say she's wrong?
Is it not possible she's right? Let's assume there is a physical God who took (takes) an active interest in the goings on of Earth and its inhabitants. Would it not be feasible that two separate groups witnessed this God doing something, and developed two separate opinions of what God is, what it wanted, and how the followers should appease it? In theory, it's very possible they are both worshipping the same God.