SOLVED. Reverse harem. Princess thought dead competes in disguise to become a royal guard to seek revenge.

[Brandy]

Series on which royal family is betrayed and murdered. The eldest princess’ best friend is party to the betrayal. The younger princess is saved by royal guard and taken to Earth. She is trained to fight for years to enter a contest to become a guard to the current prince. The princess planned to use that position to kill the usurpers that murdered her family. The princess enters under a false identity and competes in a series on challenges. Princess is trained in numerous weapons and excels with swords. The prince’s group of friends include twin boys, another guy, and a large guy from a remote area. The group somewhat becomes allies of the princess and help her escape assassination attempts by the queen and the traitorous best friend of the princess’ sister. The prince’s large friend can communicate with animals, is the favored contestant, and is punished by the queen for helping the princess, The princess also becomes friends with a co-contestant that is gay. The princess and prince’s group develop magical abilities. At the end of the second or third book, the princess finds out that her sister survived and is leading the rebels. The prince and his crew are part of the rebels/resistance.

[Kris]

Brandy, what's the full genre (which we need to add to the header/topic title) - e.g., adult romance, fantasy, thriller, romantic suspense?

How old are they main characters?

[Brandy]

I figured out the answer. It is Stealing the Throne by Quirah Casey. Thanks.