First you develop tons of names that are overcomplex and unrelatable. Now you're switching around and mismatching the names of established fantasy monsters with reckless abandon. Are you intentionally making your story difficult to read? Why don't you try keeping it simple for once and just have; Dragon?
There does need to be variation for clarity's sake. We don't just call people "people" unless we're being general or gender-neutral.
You do know this is fantasy, right? Scratch that, you know this is fiction, yes? Fiction isn't supposed to be as detailed as real life. What you have is a bunch of irrelevant details in your story for no other reason than to show off how clever you think you are. When in actuality all you're doing is weighing your story down with trivia and worldbuilding that nobody cares about.
I think you need to J.K Rowling it. By which I mean bastardize some Latin. Serpentes- snake serpentem vectem -serpent Puella-girl Puer- Boy Femella - female... obviously Draco- dragon Femina- women Man- Vir Male- Masculum Soooo a female dragon could be a Dracmina or a Dracona. A man dragon could be a Dracvir or Draculum It's technically gibberish but it'll sound intelligent.
I do not read a lot of fantasy, but enough that I would prefer "fledgling" if I were reading it. As I was reading through this thread, I was trying to remember how Robin Hobb did it, and how about the Inheritance series.
I'm going to be honest and say this really doesn't matter as much as you think it does 1. In the totality of your story, everything just seems so convoluted & nothing sturdy for a reader to get a grip on to orient themselves with 2. These terms don't even really matter in animal husbandry for the most part. Whether it was breeding my dogs or goats or whatever, it was "the stud got our bitch pregnant and in the first litter she had two girls & four boys." Goats were lazier—"Sasha had two kids this weekend, both were girls and they are just as pretty as their mom." We don't even have some gendered child identifier explicit to humans—boy & girl are vague & indefinite age ranges and can be nonexclusively applied towards any species whatever on the earth. I had a little boy last week, the puppy is a boy, it's hard to sex chicks but I think they're all girls, that kitten is most definitely a boy no matter how much you try to convince me he's a she. My lizard is a girl lizard. See? For all intents & purposes, it's as simple as a boy or girl dragon. That's it. That's all you need. Calling one something like Dracona and the other Dracvir might be cool—if that was the only unique or tidbit/factoid the author wrote in an otherwise basic, real to life story. Harry Potter could say muggle, mudblood, animagus, et cetera, BECAUSE they called nearly everything else by their mundane names—trainers, torches, platforms, trains, carriages, owlery, beds, hallways, on & on & on. You can have a sprinkling of oddities when you're grounded in the pedestrian. But when it's Kzeunar the Valiceur of Risgoth and his fledgingly dracvir, heir to the Suthenian Jevkrids— THAT's just another mess in a whole slew of unintelligible gibberish that the reader has no conception of and therefore consequently absolutely no care for. Boy & girl dragons. That's it. It can be as simple as that, and—with the complexity of everything else—should be as simple as that.
To add my 2 cents, and not having read all the posts... World building can often become confusing. For me, clarity is king, and endless terms that belong only in your world, and have different meanings to those used in the real world, become quickly confusing. Keep it simple.
Drake - young male dragon Draena - young female dragon I think you should keep your terms. I always enjoy novels that have a language of their own. It adds depth. Certainly there needs to clarity, but the two are not mutually exclusive. Put in the work and you can have your cake and eat it too (unless the Draena get it first). Best of luck.