[X] Leave the leader position for some time. Let Bertha in charge and focus on learning more about how being a leader works.
To be blunt, I think that this is in Maylene's best interest. I don't doubt her passion or drive, and the sheer fact that she's already a Gym Leader at her age speaks wonders about her. If she stayed in her position as Gym Leader, there's no doubt in my mind Maylene would give 110% to try and solve this.
...The problem is, that's the exact reason we can't let her continue as she is. Maylene has been running herself and her Gym Trainers ragged trying to keep the routes out of Veilstone patrolled, and we can see what happens when they inevitably bite off more than they can chew.
Maylene was only looking at this from the perspective of "I'm a Gym Leader, I must solve this problem", when, well, that's the utterly wrong view to take. Gym Leaders aren't just strong trainers who exist to give out Gym Badges, they're key figures in a community. A Gym Leader can't afford to just try to solve everything themselves, they need to be willing and able to ask for help from the community.
Like, Akahime and all her disciples are currently living in Veilstone. They could've been enlisted to help with patrols. They are probably a few strong Trainers who live in Veilstone that might've joined in patrols. The Veilstone Department Store would've most likely been willing to shell out for stronger Trainers to keep the routes patrolled so that they would actually get out-of-town customers. In short, there exist numerous people and resources within the Veilstone community that the Gym Leader has to be willing and able to tap. And as far as we can see, Maylene didn't really do any of that. She didn't consult with the town's current Uber Trainer to see if she'd help out. She didn't try to organize the Veilstone Trainer community to get stronger people for patrols. She didn't talk to the Department Store company to see if they'd be willing to just hire some Trainers from out of town to keep the Routes clear.
For shonen heroes, the answer to any problem is just to Try Harder. Unfortunately, Gym Leaders can't afford to be shonen heroes. They need to be able to delegate, they need to be capable of acting as a leader for the community, they need to be able to negotiate for assistance with other entities or organize their resident Trainer population if they judge a problem too big for only the Gym Leader to handle.