"You will have a room of your own" Maybe: Ou pral gen yon chanm selman pou ou ?

Your translation is perfect :)  Let me just give more ways to translate this...

You will have you own room.
Ou pral gen pwòp chanm pa'w.


You have a room all to yourself.
"Ou pral gen yon chanm sèlman pou ou." (your translation... perfect!)
or
Ou pral gen yon chanm pou ou sèl. 


Haitian Creole ↔ English Reference, Look up Haitian Creole and English Words