This is an evolved form of English, so I really can’t imagine it developing a gender system (well, again. Old English used to have gender). If anything, Trigedasleng has less gender than English, since it got rid of the gendered third person singular pronouns.
The word for “warrior” is simple enough: gona. Their word for the English language is Gonasleng—the language that warriors speak. All together, the warriors would be the gonakru.
As for “princess”, I’m not too sure about that. I suppose it raises an interesting question: How many stories would have been passed on from the old world to the third or fourth generation Grounders were seeing now? And which stories? Would the concept of a “princess” even be relevant? If it were, I imagine the term would just pass on with a few sound changes (e.g. prises), but I’m not sure it would pass on. Again, it’s a question of what stories would survive, since there isn’t much modern day relevance for actual princesses.
One of my favorite scenes from an otherwise not-so-great movie Reign of Fire (2002) takes place in the camps amongst the survivors. We come in the middle of a scene where a play is being reenacted for the little kids. After a bit, you figure out the play that’s being done in a very community theater style is the scene at the end of The Empire Strikes Back where Vader reveals that he’s Luke’s father and cuts off his hand. The kids shriek when the hand is “cut off” (he pulls it into his sleeve), but then cheer at the end. It’s clear they’ve heard this and seen it performed 100 times before, but the idea is that this is their version of a fairytale like Hansel and Gretel or Little Red Riding Hood. These are the stories that the adults knew and liked best when society was plunged into darkness, and without television and movies, this was the only way that kids were ever going to hear them.
So yeah, back to the Grounders, this is something we don’t really see in The 100 largely because of the circumstances. We’re seeing it through the eyes of the 100 and everyone else from the Ark, and life’s kind of tough for them. Everyone and everything they come in contact with is dangerous, so we don’t see much of their free time, let alone anyone else’s. Actually some of my favorite scenes of this season (not because they were really exciting or moved the plot, but just because they were interesting) were the scenes in the first episode where we get a glimpse of what life must be like in Mount Weather. We see a couple dinners; we see a pre-dinner ritual (it’s kind of a prayer, but it’s really a non-denominational way of giving thanks more to each other for preparing the food and still being alive); we see that they have a pre-printed packet of information that explains everything everyone would need to know about living life inside Mount Weather (and, realistically, what it’s probably for is for children born inside Mount Weather—it’s probably what they get when they start their version of school); we hear about what happened with the art everywhere. That’s really cool stuff! And honestly, I think one of the only reasons we can see it is because there’s a time of rest for the 47 that got captured—or for everyone except Clarke, at least. And for the Mount Weather crew, they’ve been living pretty comfortable lives for the past 100 years. They’ve had time to build up those traditions and institutions. What the Grounders have been able to do is really something we’ll have to wait to discover.