The Free City

Disclaimer: this book is lgbtq friendly, and has more than one love interest. there is no love triangle, but there is a poly romance vibe. it is teen fiction, so it does not get explicit. There are mentions of past bullying (but again nothing too explicit), a near-death experience when a character nearly sacrifices themselves for the good fo the group, and isolation-related trauma. The main character does not participate in SH and there is no SA.

Dianna is free. Finally. Now she just wants to stay that way.

Dianna was born a Super in Carson City, one of the many independent cities in the confederation. Marked at birth with a power no one fully understood until it was too late, she ended up rotting in prison for crimes she never meant to commit.
When a second chance arrives in the form of a transfer to a new City, Dianna is startled to realize just how different her new home is from the old. At the new Super Academy, she begins to understand what it means to be a friend. What it means to trust someone.

But a cityless mercenary army is on a warpath, and Dianna's new city is caught in the crossfire. Their new Super general is stronger than anyone realizes, and Dianna will need to let her new friends into her heart and face the demons of her past in order to come to terms with her terrible power in time to help save the City she's grown to love.