@Prince of SeraphsBy your example, you also make it sound like Jews were never doctors, scientist, or anything beyond "cattle" in Germany. We don't know the exactly nature of the relationship between Faunas and Humans in RWBY, whether it shares similarities towards Blacks in America or Jews in Germany, which admittedly would change a lot about what they would be capable of in terms of education. But even so, as I mentioned by no means am I not aware that the doctors efforts would have been seen as an affront from either side. Yes, there will be very powerful people who are pissed at her for using her skills to either help the faunas or help the humans. I'm sure at some point they may have even tried to kill her. But that doesn't mean she still didn't do it, regardless if she had a big organization backing her or just whatever she could scrounge around. The Peace Corps were just others who shared either her mentality, skills, or beliefs. The point was that she had the skills and the the willingness to do it, regardless of what others thought.
Even if she was by herself, taken prisoner, or even tortured, she would still continue to heal others because she wanted her rights, and she couldn't stand idly by and let people die for those rights. It's about the ideal, Seraph, even if no one else would believe the same she would. Yeah, it's highly idealistic, and in a cruel "real" world, people would sooner kill her off simply because she's a faunas, regardless of her skills as a doctor or her simply desire to save lives. But the real world isn't as dark, evil, or poor as you think it is, and RWBY certainly has very little grasp of our reality. Yeah, it can be dark too. But that doesn't mean people like that doctor can't exist, because again, which do you think is more unbelievable? Girls who can move around at super speeds swinging weapons that weigh half as much as they can as she fights nightmarish monsters and beasts, or a doctor who will go into a war zone to treat the wounded from both sides of the army because she doesn't want them to die?
And I'd like to think that it's for this exact reason that Gren highly respects the doctor, even if she hates his guts, and another reason why Gren dislikes Sapphire since to him, she essentially just called a doctor holocaust survivor "shady" just because Gren happens to know and trust her.
As for when this war was fought, I honestly have no clue. I do remember Jaune mentioning that his grandfather had fought in a "Great War", but I don't know if that has anything to do with the Faunas War or something else. Considering that there are still protest for faunas equality, I imagine that the war could have been fairly recently, perhaps some twenty or thirty years ago. I imagine that it at least was before many of the cast were born, but while their parents were still young adults. The doctor is certainly older than Gren is, and I'd say she is at least as old as Gren's father, if not older. But she's aged well.