They are rather hard to beat so I suggest buying a lot of Revives (you should be allowed to buy by now) and use them on the fainted Pokémon. Also, if you can, bring one Pokémon for each Kimono Girl that will have a Type Advantage. So that means:
Umbreon: Bug or Fighting
Espeon: Ghost, Dark or Bug
Flareon: Water or Rock
Jolteon: (This was the hardest to beat for me) Ground
Vaporeon: Grass or Electric
You should train your Pokémon more if you don't want to or can't do this, batttling trainers gets you more XP than defeating Wild Pokémon.
Umbreon: Bug or Fighting
Espeon: Ghost, Dark or Bug
Flareon: Water or Rock
Jolteon: (This was the hardest to beat for me) Ground
Vaporeon: Grass or Electric
You should train your Pokémon more if you don't want to or can't do this, batttling trainers gets you more XP than defeating Wild Pokémon.