Sala hasn’t been seen by anybody in this lifetime, and based on how vague the stories are about her, it is likely it has been several lifetimes since anybody has seen her. In fact, there’s no written record of her that anybody is aware of, she is only known as “Empress”, “The Empress”, etc.
It is known is that she is divine, if only semi-divine. It’s somewhat blasphemous to admit that she is only semi-divine, so be careful who you say that to.
The stories mostly point to her climbing the Endless Stair. Perhaps her journey on the stair is not complete, and therefore her divinity is also incomplete.