Planet Urth by Jennifer and Christopher Martucci
Decent enough post nuclear slash chemical warfare apocalypse. A teenage girl is alone in the woods with her 8 year old sister, several generations after the war, qnd a year after the death of her father, the last remaining member of her family. They hide by day from the vicious urthmen, remnant mutants of humanity exposed to the radiation and chemicals, and by night from the lurkers, vicious creatures that roam the woods and that even the urthmen fear.
Driven by desparation to hunt much further afield than usual, they discover they aren't the last humans around after all, when they run into another family.
The plot is good, and I liked the dynamic between the two sisters. Decent worldbuilding, a little humour and it captured well the older sister's quiet desperation trying to look after her little sister.
Less fun, the first person pov, but it wasn't too horrible. Big sis is of course preternaturally gifted at fighting etc, and little sis is preternaturally adorable. And of course the other family has a teenage son because of course they do. And of course the first thing our heroine thinks upon spotting him is to wonder if he will find her hair colour appealing. No actual romance (yet) though, although there obviously will be.
A fast read, only 130 pages (and 5+ of that is backmatter advertising and a truly awful author note). As a series opener it's not bad, has a story arc of it's own but a clear lead into the next part of the tale rather than an artificial cliffhanger.
Not epic literature, but pleasant enough if you like YA post apocalyptic.