Idk guys, as a Mirabellfag myself I actually like how she's a mix of melee and ranged moves. For me she tends to shred through everything and hasn't let me down. It's tended to be true since getting her that if I can't beat a stage with Mirabell, I can't beat it with any character.
Of course, I tend to stay out of the tierlist discussion because my interest in Mirabell is less "is she meta" and more "awooga muscle mecha mommy"
(But seriously my wife is not low tier)