Estella would wish for eternal youth for herself and her team, so they can keep adventuring and competing forever together

Elio, quite literally, would wish for one of two things:

1.) To un-alive every Pokemon Hunter and Poacher in existence since they are a literal bane to his, being the focus of so much strife he goes through on a basis (estimated do be precisely 77%).

2.) To bring his parents and grandmother back to life, which would make his older siblings and grandfather extremely elated.

Both Jin and Mary's wishes would be pretty similar in that they'd want to have the chance to see the parents they lost again, even if it was only once. Well in Jin's case it would actually be her first time seeing her parents ;w;