I don't think Mash is Supersonic, or at most he doesn't always fight at that level of speed, more like he can accelerate up to that level.
Even then we'd be relying on a character statement from a character that's weaker and slower than them. This same character
contradicts this statement in Chapter 61 when they explicitly stated that Mash is not as fast as sound, or not fast enough to catch someone who moves at the speed of sound, on top of two other, stronger characters agreeing with him. So it's safe to say we can't rely on their statements, at least in this particular fight.
Mash had to limit Macaron's movements into two directions and he barely caught them.
Same speed issue with this:
I Already made
This Little prototype of Margarette Profile idk if there's still a lot missing or no, Cmiiw.
Why would Macaron's attack speed be rated as
Subsonic, and Sound Metamorphose be rated as "
higher" than
Supersonic when both of these things are explicitly stated to be
Transonic? Correct me if I'm wrong.
Macaron themself aren't Transonic, only with their Magic. With Metamorphosis do Macaron actually moves at Transonic speeds. Macaron was overwhelming Mash who couldn't tag them at that point, and Mash had to rely on sensing Macaron's attack before it actually hit him via sensing the sound that travelled faster in the ground to the wall (Chapter 60).
In other words we have to evaluate their other speed feats as they're most likely not supersonic.
As for Macaron's Gender, they identify themselves as Female. They're biologically ambiguous however, though that's sex.