I'm having the Gym's layout be akin to those in the games.
...
Ash was looking through applications from trainers requesting to work at the Gym, as it had become necessary for Gyms to put challengers through "Qualifying Matches" before they could battle the Gym Leader. Ash had sent out a request for each skill level, determined by the number of badges a challenger had, except for the 0-1 Badge skill level, since Ash had already registered his daughter for the qualifying matches on that level. It was a painful process since they didn't know her name, but they managed it.
The way he had the Gym set up ensured that the challenger would go through two battles before battling him. There were three platforms. The lower platform was for the qualifying matches, once complete, the Gym Trainer would give the challenger access to a lift that would take them to the middle platform, where they would battle Torracat to earn it's trust and then work with it to solve the puzzle to activate the lift that would take them up to the highest platform, where Ash himself waited. What allowed this arrangement to fit the fire typing of the Gym was the fact it used steam lifts, or geyser lifts depending on who you asked, rather than hydraulic lifts.
A loud crash distracted Ash from his work. He left the Gym's office and made his way to the main area. He wondered what could've made the noise since it was just himself and his daughter there, as well as their Pokemon. Ash entered the main area and saw a surprising, yet not unexpected, scene. The location of the Gym used to be a preserve, before Neon Town became the noisy place it was known to be, so when the Gym was being built, everyone, whether they were applying to be the Gym Leader or not, was warned that there may be some ghost types lingering around the area. Ash had been expecting a confrontation since being told he would be the Gym Leader, but he didn't expect them to be polite about it. Yet here, before his eyes, was a Misdreavus confronting his daughter and her Growlithe in the middle of their training to get used to the battlefield.
"Growlithe! Use Bite!" Growlithe charged at Misdreavus, fangs bared. As soon as it jumped to sink its fangs into the ghost type, Misdreavus shot it out of the air with Psywave. "Return!" She brought out Growlithe's Pokeball, but Misdreavus prevented Growlithe's escape with Mean Look. "Use Flame Wheel!" Growlithe encased itself in fire and shot itself at Misdreavus, scoring a direct hit, but Misdreavus bounced back with Astonish. "Use Leer! Then try Bite again!" Growlithe executed the combo, lowering Misdreavus's guard with Leer, then sinking it's teeth into it. Misdreavus freed itself from Growlithe's grip using Psywave, then hit it with Confuse Ray. "Oh no!"
"You've done enough damage!" Ash called from the stands, "There's only one thing you can do without putting Growlithe at risk!"
She thought for a moment, trying to figure out what he meant. When she finally understood, she pulled out a Pokeball and tossed it as Misdreavus went in for another Astonish. The ball struck Misdreavus and sucked it inside. The Pokeball wobbled for a few moments, making her anxious, before clicking. She stared at the now immobile ball in disbelief. Slowly but surely, a big smile appeared on her face. She ran over to the Pokeball and picked it up. She had caught a Pokemon in front of her dad. This somehow filled her with more excitement than when she caught Growlithe, she just couldn't contain it.
"I DID IT!" She cheered, tears of joy escaping from her eyes. She waved the Pokeball to Ash, "Did you see it dad?"
Ash gave her a thumbs up. no matter how excited he was with his daughter's achievement, he had to show some level of professionalism as an adult and a Gym Leader. It was a good thing he put on his adult face, because the main doors opened and in walked a surprising visitor, Gary Oak.
...
Sorry if the chapter is short. I just wanted to establish one of Ash's daughter's non fire types. It's also safe to say that she'll go on her own Journey after regaining her memories. I have her teams for Kanto and (partially)Sinnoh figured out, as well as her Johto starter, but I would appreciate your input. I'll share what I have for her teams so far.
Note: Vulpix and Growlithe are her Gym team and will not join her on her journey.
Kanto
1. Bulbasaur- Ivysaur- Venasaur
2. Misdreavus- Mismagius
3. Machop- Machoke- (Trade for) Alakazam
4. Scyther
5. Poliwag- Poliwhirl- Poliwrath
6. Rhyhorn- Rhydon
(PC/ Rotation):
Aerodactyl(From Old Amber, courtesy of Brock), Primeape(technically Ash's, she's just returning it to him)
Sinnoh
1. Chimchar- Monferno- Infernape
2. Shinx- Luxio- Luxray
3. Scyther- (Temporarily trade for) Golem- (Trade back for) Scizor
4. Onix- (Trade for) Barboach- Whiscash
5. Absol- (Trade for) Glaceon
6. (Open slot)
Johto
1. Totodile
2. (Open slot)
3. (Open slot)
4. (Open slot)
5. (Open slot)
6. (Open slot)
I'm sure you guys will think up some good teams.