If you ask her whether she is the literal daughter of Selune, she says Selune is her birth mother. I didn't get the impression she was unsure. However, Larian has many inconsistencies, to the point it's difficult to tell whether something is mistake, oversight, or a hint. Re: Astarion's tombstone. How old was he when he was turned? He may not look like a teenager frozen in time, but that's apparently what he is.
