We need to talk about Tina

I just started reading. Kinda bummed out, since I expected more of this story and there's already so much that annoys me, but the last chapter I read - Chapter 5 - really took the cake.
Tina is such a dumb fuck, I can't even.
Sorry for everyone who likes her, I mean, it's my opinion and you obviously don't have to share it, but I need to get this rant out of my system.

Dyan tells Eric and Tina to go back to the village and inform the others, so they can return with seasoned hunters and help him out. That's the most sensible thing to do in that situation, since Dyan might survive this, but children would only turn into a liability.
I don't want to say that Eric acted great in how he lets her have her cake and eat it, too, but he at least starts off by putting her into place. She's a child without any experience and Eric can't do too much either, since he's also only 8 years old and his physics won't change, so long as the lore doesn't give any feasible reason for it to be otherwise. The Problem ist, that the narrative of the story seems to be aware of the fact that two children running into a fight would simply endanger everyone involved, by having Eric apologize the moment he decides to enter battle alongside Tina, who's selfishly charging in.
The thing is: Since it ended well - because what else would have happened, really? - no one spares a thought, but if they had all died, who would have been to blame? She only managed to do this, because she remembered wearing her plot armor, otherwise, she wouldn't have gotten out of this with barely a scratch, when having literally no experience whatsoever, because that's not how it works. At this point, Tina is a Mary Sue.
Yes, I said it. She's a Mary Sue. I said that, in the context of a story which will probably end up with a very strong protagonist. But here's a fact: It's not overpowered, as long as the character actually had to work and go through hardships to become powerful. He has to be somehwat responsible for his strength. For example, in Kill the Hero, it seems like the protagonist has it waaaay too easy, but even then, it's not a Mary Sue, since he learned all of his abilities and had to go through a life of hardships to get to the point he was at the beginning of the story. With the experience and training he had, it's obvious he would excel. But Tina is just a child. Even if she's fucking gifted, there's no way she could use her powers in such a situation with such confidence and accuracy. But even if I stop there and get over the fact that she's a broken character, that's not even the real issue of that scene.
The real issue was that goddamn speech she gave Eric. The fault I find with that speech is the fact that the narrative of the story seems to shift that very moment. From Eric, rightfully apologizing for not heeding his father's order, endangering the whole village in the process, to Tina, as she rambles on about how she wouldn't want to live on, if she was the only survivor (coincidentally forgetting about Eric, who would also survive and acting as if she cared more about Eric's dad than he himself does). But reality check: Saying something like that isn't an act of bravery, but an act of cowardice. You jump in because you are afraid of loss, but make the other's sacrifice obsolete in the process.
In the end, she gets to have her way and Dyan only tells her how he's proud and thankful. The fact that her egotistical behaviour could have easily killed all three of them, endangering even the viallge - which isn't warned because she didn't want to return and call for backup - is not even mentioned by anyone. In fact, they simply brush it off.
She should have thought about these things, because the whole time, this Manga is trying to portray children as adults who can see the bigger picture, so I expect her to see that far ahead, too. And if she can't, fine. But then make it a learning experience instead.
I wouldn't have been so pissed at this scene, had there been someone smacking her upside the had a few times in anger afterwards. At least a stern talking would have been called for. Like that HeroAca Scene, when a few students tried to help save another, which wasn't allowed and could have ended terribly. The homeroom teacher then talks to them in a way that perfectly conveys how disappointed he is, all jokes aside, and how he would have ejected them from their hero course, if it had been up to him and if the circumstances had differed just slightly (because a lot has happened, so he let them have it, but he gave them a clear warning about acting out like that again). Because stupidly endangering yourself and others is neither brave nor intelligent. It's stupid and shortsighted.
But in this story, somehow ... nobody cares.