If you don't want to catch and train a new pokemon, because that's quite frankly a pain in the ass, my suggestion would be to keep her Muk alive at all times and gangbang her other pokes with your 2. Muk might be a minor pain in the ass with disable, but he's the least threatening thing on her team overall because of its pitiful special attack. Once you get to Dragalge start hammering on it with Slaking and Skuntank.
Also, it might help to force her to expend some of her potions early on on her less threatening pokes, like Tentacreul or Muk. Just fall short of KOing them and she'll heal so that she doesn't use Hyper potion on Dragalge later on.
If you can spare the time to train a 'mon, Quagsire/Gastro are good choices and level up easily in the wastes. Quag gets Earthquake in the early 30's, too, which will be quite devastating.
I just beat her with a team worse than yours (In my arsenal are Emolga and Bibarel, for example) with no ground or psychic types. Good luck.
