Although small and no doubt somewhat weaker than the normal variety, Hyacinth is none the less quite obviously a Dryad of some type.  She stands just three feet tall and is often found wearing a heavy covering of bark and wood that makes a bit of nose with every motion, those motions themselves come with the creaking sound of trees in the wind, if small ones.  So very little about her is subtle or quiet.  Even when she talks her voice sounds like some sort of reed instrument cleverly configured to produce words.