Arlecchino isn't actually from Fontaine? 

your answer lies in her Story Quest

Im pretty sure she's a glitch in Teyvat so forget abt Fontaine lmao 😂😂😂 she's full on alien 👽

Can you look at her vision?

She was probably born somewhere else so it doesn’t count

being fontainian isnt what determines if a character can do a dolphin jump, its them having a fontanian vision with an arkhe. arlecchino has neither, but she _is_ from fontaine.