I'm making an official guess as to who Tamara is...
Crazy with that taser:
And manipulates men with false identities:
She certainly knew a lot about potion making as well as magic
AND before she took the potion she admits that she wasn’t “quite human”:
There was also the magic in a bottle hint and she sat by a fish tank.
She manipulated August, who’s greatest desire was to be fully human (August/Ariel parallel)