The little mermaid was my favourite movie growing up so Ursula is calling out to me. It should be simple--just a black dress and purple makeup.
She has white hair.... and i cannot afford a wig atm
What about the spray on hair color? Or I know one kid who got pretty close to white using hair gel/spray and baby powder.
But you have the same hair style so you don't need a wig. Id look up cheap alternatives even if you cant get a spray on hair colour. Chalk or baby powder come to mind though youll have to actually poke to see <3