Midori

Midori is a character of the day who appeared in The Evolutionary War. She lives on Island B of the A-B-C Islands.

When Ash and his friends arrived at Island A of the A-B-C Islands and visited a Pokémon Center there, Midori called the Center's Nurse Joy. Midori explained to Nurse Joy that she was worried that her Corsola had caught a bad cold, and sent it over to the Pokémon Center so Nurse Joy could examine it. After she did this, Midori said she would come to the Pokémon Center later on.

(Source: Bulbapedia)