Myr was very much different from the Myrtle Warren that switched places with her via the Mirror of Destiny.
Where Myrtle had lived her life in self pity and complacency, Myr set out to change it.
Myr at the tender age of 4 convinced her father to get back in contact with his own estranged one.
At 4 she beat her grandfather at chess, gaining his interest.
By 8 Myr had convinced her grandfather to invest in several strategic businesses, predicting he'd find himself quite wealthy in several years (when WW2 would prompt certain industries to flourish).
Also at 8, Myr found herself at Gringotts and had made a deal with the goblins regarding several other businesses she couldn't let her grandfather know about, some stretching far into the future.
If they hadn't recognized her as a Tempest, perhaps it would have been harder. If she hadn't made a wish to be a non-magical and magical polyglot, maybe it would have been harder.
It was there where she discovered that the Warrens were a squib off-shoot of the family of Travers. It was there that she found an interdimensional journal that gave her ideas for wishes that will allow her access to the wizarding world and Hogwarts.
By the time she was 11 in 1940, she had a nice little nest egg in both worlds. Her grandfather took it rather well that she was a mage (perhaps that had to do with the dusty hidden rooms in the estate, potions room and library) her parents however did not, leaving her in her grandfather's care.
Unlike Myrtle Warren that entered Hogwarts ignorant to the rules in place for society, Myr was well equipped. And when Olive Hornby and her friends tried to harass Myr they found similar things happening to them, and the best part when investigating all evidence lay on their shoulders.
By the time Myr was 13 in her new world she was equipped with several safety net wishes, just in case fate was cruel and she found herself on the path of the previous Myrtle.
Myr didn't believe in fate and yet when she nearly finished third year, seemingly unaffected by the several petrifications that rocked the school, and found herself in the second floor bathroom staring into the most beautiful deep green eyes she'd ever seen she questioned her stance.
~My what a beauty.~
Parseltongue came as easy as any other beast language to the Tempest. Staring up the massive basilisk who preened from the praise, before looking at her with a curious cock of the head.
~Are you a snakeling from my old master too?~
Myr chuckled, ~I have no such ancestry but I can speak to all beasts big and small.~
The nostrils of the serpent flared, ~You smell of storms.~
~As I should.~
~Something ancient and new, you are a contradiction, little storm.~
Myr gave a curtsey to the serpent queen,
~Majestic queen please tell your new master I mean no harm.~
As Myr turned she heard a muttered hiss from the opening in the floor behind her.
With an apologetic hiss, the basilisk striked only to let out a confused hiss when her fangs did not pierce Myr's shoulder.
~If they wish to kill me they will have to try harder than that. Goodbye, my queen.~ Myr bowed and felt as the great beast licked her cheek before Myr turned on her heel and left the bathroom.