it's a reverse transmigration (kinda LOL).

So MC died in an apocalyptic world, saving her comrades, and then woke up in the body of the Duke's youngest daughter in another world (or is it?). But this world is a peaceful one that never knows about the monsters she's facing in her world before. So she tried to adapt, but suddenly BOOM! The monster that she deals with in another world appears in this world, and BOOM! She also met some people who have similar face and personality to her comrades in the apocalyptic world. So now she has to find out why she transmigrated into the Duke's youngest daughter and why the monster and people who have a similar face to her comrades appear in this world

MC is not a damsel in distress, she actually one of the best attackers in her group. And also, I love that the author emphasizes her experience and trauma in the apocalyptic world and how it makes it difficult for her to adapt to this new peaceful world like one example

Her trauma triggers when she smells Patchouli because in her before world, this smell indicates that there is a monster among them and the monster is devouring or metabolizing other humans. But in this new world, the Patchouli is used as an everyday bug repellent, so the smell is everywhere.

And also, I love that MC does not dismiss her experience and is even proud because she knows that her experiences are what made her who she is today and enabled her to survive.

So when she was busy surviving, she and her comrades came across Named monster called Mimic. This monster was so strong that when they battled it, out of several hundred people, only less than ten survived. In her first experience meeting this monster was when one of her good friend came to the barracks with the smell of Patchouli (so the monster was already devouring her friend as it mimicked her friend, imagine it like the monster from Kiseijuu/Parasyte). So it became one of her traumatic moments.

But suddenly, in this new world, she met this same monster, but with less than ten people who could fight it, and many people to protect, and also with her other friends occupied fighting another monster somewhere else, so she could not call for support or help.

And damn, the scene when she tried to battles it, like so damn cool!! I can read her desperation to not to let the same thing happen again as before.