This can be accepted as a slice of life webtoon and deserves get 9 and 10 out of 10.
The protagonist is smart. She grew slowly as a child.
Not forced to behave as an adult as in Lady Baby and too naive as in Child of this House.
For stories that take on an unusual family environment, this is far better than Who Made Me a Princess. The explanation of the magic is also not confusing. I think the author has fulfilled the responsibility of using the concept well, not just being introduced it at the beginning. Who Made Me a Princess has no love in it, I may be left out because I feel that many important scenes from the novel, too many jumping scenes. It's the exact opposite with The Youngest Princess. I feel comfortable with the timeline, which moves well. (Okay, this is quite subjective on my parts but that's how I look at it another way. There are different influences between pure reincarnation of the fantasy world and grow into a little princess by the surprise route of the Otome game.)
The warmth of this webtoon is also the same as Child of this House. The pair of father and brother who have wild and terrible personalities can be tamed easily enough. Because both of them have the same element, I can't predict whether it will slow burn either. The Youngest Princess takes a world that emphasizes how strong the role of magic is, and the existence of a third star that will shake both the empire and the Arcus, as per I made this review, most likely we will not enter into conflict before she grows up. It will be interesting if we have the main villain sooner though.