Since when has Shar been a major goddess? Since Baldur's Gate II? Since some licensed novel series? I've only known Shar as a minor deity, and while my FR knowledge is unsought for, and an edition or two out of step, none of that changes the fact that the story the game is telling trumps it. If Shar is a minor deity, or a forgotten deity or if nobody recognizes her iconography on sight, so be it.
I think the truth of the matter is , the DM considers this issue to be resolved so early on that it isn't a big issue for them.
