Persistent and determined, courageous, rebellious, stubborn, with strong sense of justice, not sassy. Also Pocahontas( mostly because because of her persuasiveness) but Miriam is less indecisive.
Miriam isn't exactly like any DP, she is very much an original character. But her combination of courage and rebelliousness with maturity, her selfless and lack of sass makes me think of two late Renessaince DPs.

@Adelital too bad Miriam isn't Disney, she would make a wonderful DP.

^ Agree, pretty unique character.

She is very wise and stands up for her beliefs. :)

oh look, it's my wife >

They would totally get along though. Similar spiritual outlook, they're both willing/able to see the potential in others before anyone else does. Both fairly impulsive as well, and tend to take big personal risks for other people & for their principles.
They're also the characters with the greatest influence on the hero's moral development.
I can see a lot of Mulan and Belle temperamentally - she isn't volatile like Tzipporah, but also isn't down to take anyone's bullshit either. She can be quite blunt and stubborn when faced with pushback.

imo Dreamworks women wouldn't translate well to the DP universe. Which isn't a bad thing. Not every heroine needs to be a princess.

^ My favorite things about Miriam are exact reasons Pocahontas is my favorite DP.