Not that we know of; in the games, Mallow is shown to have three Pokémon, but in the Manga and the Anime, Mallow only has one. Tsareena is her trusted companion throughout the series. She doesn't catch other Pokémon because her goal is to be the best chef, not a Pokémon master. She is shown to care for other Pokémon and make friends with them, like Shaymin, who she took care of for a while.