From Bulbapedia, the community-driven Pokémon encyclopedia.
Mollie (Japanese: ミカ Mika) is a character of the day who appeared in What I Did for Love!. She is a rookie Pokémon Coordinator who made her Pokémon Contest debut at the Gardenia Town event.
Mollie seemed to have trouble finding out where to register until Brock told her it was at the front desk. Her Raticate's Appeals performance helped Mollie advance to the second round. She used Absol, but the two lost to Brock and his Marshtomp.
In the end, Top Coordinator Yuma decided to take Mollie under her wing and develop her Coordinator potential, as she felt that Mollie needed more advice than Brock.
This listing is of Mollie's known Pokémon in the anime: