So...
1- She is a noble who was given no money or a single territory, which means she is equivalent to a figurehead or a commoner slightly above other commoners.
2- She is a baby that is completely disregarded the fact that her body is frail and she could die easily due to the fact that her body is extremely under developed.
3- She is to be sent to battle with less than 1 year old because it is "safe" (to an adult).
Why this is all stupid.
1- She is basically being treated as a slave and not a subject. Ordered around with no reward whatsoever, which makes the king stupid, reckless and a tyrant. The literal worst kind of king.
If she dies, due to his own stupidity, he loses the most extremely valuable resource that he currently just got.
Also, he is giving her no meaning or motivation to be loyal to him, as a title with no backing up that title means literally nothing but a name.
2- Even if she is powerful, she is frail, and she should, specially for that reason, be given time to grow at least till she is 7, preferably until she is 15 years old.
If she dies for their reckless handling of her body, they are imbeciles.
Even if they are 100% sure she is a reincarnated person, it is extremely clear that SHE IS A FUCKING BABY.
HER BODY IS THAT OF A FUCKING BABY.
Treating her as an adult because her mind is an adult is a collective insanity and stupidity and gives an extremely bad taste in the mouth that the author is not paying attention to his own scenario, because so far, no one treats her or asks others to treat her as a baby so as to not endanger her life for stupid reasons.
3- Read back number 2.
SHE IS A GODDAMN MOTHERFUCKING BABY!!!!! Even if she can win due to her power, they are all bloody stupid idiots because they are putting her life in danger for no reason besides "I want a show. I want to see baby power" and that is both stupid and frustrating.