Despite all the art otherwise here, Azure Star is (at the time of this post) still canonically a Unicorn, albeit one working diligently to change that. The only solid visions of possible futures where she’s ever actually seen that she really could become one for certain are actually of timelines where she fails to save Luna and instead takes her place by Nightmare Moon’s side upon her return.
But that’s not the only way for her to do it, right?
Also biting the bullet with the tagging and putting the weirder implications out there for the world. She’s an artificial child made with stolen DNA by a supervillain that cared more about results than avoiding inbreeding. Blame my GM/Solredrose.