From Bulbapedia, the community-driven Pokémon encyclopedia.
Marigold (Japanese: モモッチ Momocchi) is a character of the day who appeared in Clash of the Connoisseurs!. She is the daughter of a wealthy man named Mr. Hatterly, whom she lives with in an enormous mansion just outside Stonesthrow Town.
Her father hired Cilan and Ricard Nouveau, both of them A-class Pokémon Connoisseurs, to help her pick out her starter Pokémon. Unbeknownst to them, Marigold already had a Pokémon friend that she played with secretly in her backyard. Cilan, Ash, and Iris eventually figured out it was a Foongus by its unique scent, and Marigold explained that she was afraid her father would not like it, which was why she kept it a secret from him. He did not mind at all, however, and she was allowed to keep Foongus as her friend.
Marigold is known to be rather shy and would hide behind her father's leg whenever Cilan or Ricard wanted to ask her a question. With her Foongus, though, she is shown to be especially playful and happy. She is also a bit nervous to explain something like her desire to have Foongus as her partner and that she had been secretly playing with it in her backyard.