Known C A N O N facts about the Mandalorians:
A) Overall, they do not view/value "gender" in the same way other cultures in SW (or those in our own world) do.
B) Color symbolism, paint design and the amount of beskar you have on your armor is viewed as a main/sole identifier of a Mandalorian.
C) Mando'a, the language of the Mandalorians, does not have gender signifiers. Mando'a is a gender neutral language.
D) Your gender, your sexuality, your race, your previous life, etc does NOT matter after you have sworn the Mandalorian Creed. You are a Mandalorian and will always be Mandalorian, unless you violate your Creed.
-Cin vhetin: a fresh start/clean slate. Literally means "white field."
-Gar taldin ni jaonyc; gar sa buir, ori'wadaas'la: "Nobody cares who your father/parent was, only the father/parent you will be."
-Aliit ori'shya tal'din: "Family is more than blood."
In conclusion, the only thing Mandalorians really care about is how skilled of a warrior you are and how loyal you keep yourself to your creed. They do not give a fuck what your gender identity is or who you choose to fuck.
To put it more simply: Can you hit real good? Do you have honor? Okay then.
Verd ori'shya beskar'gam: "A warrior is more than their armor"
Tldr; I'm getting really tired of people trying to act like the Mandalorians as a whole would have a problem with a trans/nonbinary person being a fellow Mando. The answer is no. No, they would not.
(Update: Meant to also say the same fucking goes for your sexuality, but I feel like I'm just beating a dead horse at this moment. You guys get the fucking point)