Almost all girls are done growing by 16, and won't gain any more height or bust size. Typically they are mostly finished by 14 and only grow a small amount after that. Boys are slower to finish growing and for some reason people tend to think of the male growth rate as being normal.
Technically...
The issue is that while it does have a strap, and could provide a lot of support vertically if well shaped. If it provides any sideways support it would have to compromise on core movement with fairly ridged structural elements, because there isn't the option for using the back to provide...
Well the wall behind her is smooth, one could assume, that above what appears to be wood wall panels, it is plaster. Maybe the lower wall near her is too. We also don't see the floor, so it might not be wood. So it could be worse, and I'm sure that these illusions will be shattered because the...
I wasn't sure if it's more of a sasuga, or shikata ga nai situation. So I guess, as expected of the one who killed the demon lord, it cannot be helped.
They've done meals for three twice now, and she has eaten with a coworker without her landlady. They might move onto group meals, or maybe even catering.
At the end of chapter 11 she "reincarnated" a bunch of her subordinates. Since then the armor has apparently gotten far larger. They don't recognize the suit of armor because it's effectively a different suit of armor, and as they noted, huge.
It's just that this is not the direction I was expecting from a gemstone wanting to be an accessory. I was expecting a piece of jewellery with a prominent gemstone.
If you are going to seal a guy away, why would you make it so the seal can easily be broken by his descendants? It's not like it took effort, he just touched the wall and walked in. I can only assume this is a weird flaw with the sealing method rather than something intentional.