I think they're all unusual enough but not too unusual

I'm a Holly - I don't know anyone else called Holly except for HollyM & Hollye on here

I teach an Ellie (spelt Elle) - she's the only one I know & she's 16yrs.
I teach quite a few Georgia's (or Jorja's) - but no Georgies
I only know of 1 Bronte in DS's class at school,
Don't know any Gracie's, but I teach a little girl called Graycin - she gets Gracie for short

I think they're known enough to not misunderstand or mispronounce them, but not common enough that you should double up at school etc... they're all lovely