a Mestra

teacher, mentor, master

m ɛ ʃ t ɾ ɐ → mestra
mestr teacher; master + a feminine singular
noun · feminine Rare #37,616
teacher, mentor, master A female teacher or mentor; in some contexts, especially martial arts, “master” is the natural translation.
PO: Minha mestra me ensinou a ter paciência.
EN: My teacher taught me to be patient.

“E, portanto, nossa Mestra dos Navios deve insistir com o Capitão do Porto.”

And therefore, our Mistress of Ships must press the Harbor Captain.

Desde quando você fala assim com sua Mestra?

Since when do you speak to your Master like that?

— A Viagem de Chihiro (2001)

Sou a Mestra dos Navios Kirasdotr.

I am Master of the Kirasdotr Ships.

Sim, Mestra-Proprietária Kirasdotr.

Yes, Mistress-Owner Kirasdotr.

Estão examinando nossa conversa com a Mestra dos Navios Kirasdotr.

They’re examining our conversation with Kirasdotr, the Mistress of Ships.

Sounds similar to