Yes, there is no scripture to support the idea that she is sitting on a throne in heaven. Of course, absurd theology says, "just because it doesn't say so, doesn't mean it's not true", which is why some religions, that insist upon worshipping the creature, rather than the Creator, must resort to extra-biblical revelation to support their gnostic wisdom.
Then, of course, they can pull a verse out of the bible, ignore the other biblical references that support its meaning, and make up theology out of whole cloth, yet deny it's their YOPIOS.