QQ sweeper? the sequel is called Queen's Quality. might be wrong tho, sorry!
Unfortunately that isn't it thanks for trying though!
this sounds interesting want to see if someone finds it.
Ive been putting in tags that I think it might show up as and it isnt getting anywhere....I know the girl has really long light colored hair. I want to say either her family is dead, or they dont have anything to do with her I cant remember which. She also has an attendant or a knight that is always with her....
Have you tired asking on mangaupdates that's usually the places i find manga I forgot about.
I'm looking for a manga about a princess (or queen) that has a power to use her voice to command. I'm not sure the manga is complete it might be. I think she also has power over some sort of animal....I might be wrong. (I'm not talking about the manga her majesties dog where the girl uses kotodama)