Mizuho

ミズホ

For a brief period, she served as the Gym Leader of the Pewter City Gym, officially known as the Pewter Gym, and awarded the Boulder Badge to challengers who defeated her.
Lola is married to Flint and has ten children. One day, Flint left to become a professional Pokémon Trainer and never returned. Sometime after that, Lola herself wandered off to train Pokémon, leaving Brock in charge of his many siblings. One of Lola's many hobbies is decorating.
In the Chronicles episode A Family That Battles Together, Stays Together, Brock returned to Pewter City after traveling through Kanto, Johto, and the Orange Archipelago and discovered that Flint was shirking his Gym Leader duties. Flint explained that the Gym was ruined because Lola had returned. She had completely redecorated the interior and exterior of the Gym, planting a series of trees and bushes outside. She also filled the interior of the Gym with water and decorated it with streamers and pink hearts and stars. Flint ended up closing the Gym because he couldn't stand it anymore.
Brock returned home to find his mother cheerfully redecorating the house. Lola gushed over her own work and showed off her Water-type Pokémon, saying that they were much better than Rock-types. Brock demanded to know how Flint could let this happen, and Flint explained that he just couldn't say no to his wife.
Lola and Flint had a rematch for the title of Gym Leader. Flint was sure he would lose due to type disadvantage, but Brock pressured him into the battle anyway. Flint's Pokémon almost ended up drowning in the match and had to be resuscitated. Flint was almost ready to run away again, but after some flirting, Lola and Flint ended up being lovey-dovey with each other, and the two agreed to change the Gym to specialize in both Rock and Water-types (to their children's dismay).
Not ready to give up, Brock decided to battle his own mother to keep the Gym the way it was, and he came out victorious. Lola said she would give up trying to change the Gym's type, but Flint managed to persuade Brock to let Lola keep the decorations, even though she was supposed to take them down if she lost. Brock passed on the title of Gym Leader, along with most of his Pokémon, to his eldest brother, Forrest.
Lola also made a short appearance in Grating Spaces!, where she went on a trip with her husband and Brock's Ludicolo, leaving their children alone at home. When Brock came home and found out that the Gym was remodeled and they were leaving, he became mad at both his parents. The couple and Ludicolo later came home at the end of the episode.