SOLVED. YA Sci-Fi: In a futuristic space empire an aristocratic family buys a feral girl as a bodyguard for their daughter who has to take the role of the daughter. [s]

[Dakota]

The daughter is set to meet with the future heir to the empire who is seen as a lunatic and possibly mentally disabled. The family decides to send the bodyguard in the daughters place, but need to teach etiquette to the bodyguard who only knows how to kill. At the event it is revealed the heir to the throne has been faking his insanity as to not be seen as a threat by the current emperor. The bodyguard and future emperor fall in love by the end.
Other vague details I remember is everyone lives on spaceships. The emperor is the possibly the boys uncle.
I read this book around 2018 or 2019 at the library by chance and can't remember the name.

[David]

Searching with "sci-fi bodyguard disguise daughter site:goodreads.com" returns The Diabolic by S.J. Kincaid.

"Nemesis is a Diabolic, a humanoid teenager created to protect a galactic senator’s daughter, Sidonia. (...) Nemesis is expected to give her life for Sidonia, and she would do so gladly."
"When the power-mad Emperor learns Sidonia’s father is participating in a rebellion, he summons Sidonia to the Galactic court. She is to serve as a hostage. Now, there is only one way for Nemesis to protect Sidonia. She must become her."

[Dakota]

David wrote: "Searching with "sci-fi bodyguard disguise daughter site:goodreads.com" returns The Diabolic by S.J. Kincaid.

"Nemesis is a Diabolic, a humanoid teenager created to..."

That's it, thank you.

[Kris]

Glad you found your book, Dakota.

The Diabolic (book 1) of The Diabolic series by S.J. Kincaid - David's find.