Yes, but it is better to refine it first. There is no reason to give it vote manipulation, so it shouldn’t have it. Tbh I see no reason why not reveal immediately. The BD knows you aren’t evil and that you generally side with them. I feel we don’t want give out anonymous communication like candy. It would be better to find some other ability to spice up the protection.
GENERALLY it doesn’t mean she will sided with BD to the very end. Just saying there may betray BD like other neutrals when she find out last guy with royal blood is evil. Someone suggested to expand more her win condition: “Queen also need to survive until end of the game”, which can prevent fearless outing herself to court as Queen, also you’are not guaranteed to be protected by healers or knight considering you’re neutral who can backstab them in the most sudden situation,