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Katrina (Japanese: クミコ Kumiko) is a character of the day who appeared in Time Warp Heals All Wounds. Edna and Jonathan are her maternal grandparents, and her mother was mentioned briefly.
After running to Fuchsia City's abandoned train station to retrieve her grandmother, she also met May. Katrina informed her that Jonathan had left Edna to work in the big city and died there, and that her grandmother had lost a very important amulet during that time.
After May and Meowth rewrote history, making sure Jonathan wouldn't leave the town and instead stay with Edna, she reappeared alongside her grandparents as their assistant in caring for baby Pokémon. At the Pokémon Center, Katrina watched as May's Egg hatched into her Eevee. Because May had altered the past, Katrina didn't remember her from before.