How about some pants? She's half dressed for winter and half dressed for summer, places she goes she's probably freezing wearing that skirt thing.
I should have been specific, I meant like a Pokémon as a gift, jewelry, that kind of gift, but I understand where you are coming from
I would give her a Pokémon, maybe a fairy type, as a coordinator I can see her rocking a Sylveon. Though to stay generational Gardivoir/Gallade could work or a Frostlass, maybe even a Lumineon.
Dawn has a full team so I can't see a Pokémon....I can see her appreciating new clothes or Piplup items, she was very happy in the May episode when May gave her a Piplup necklace.
I suppose something to give the Pokémon like berries, or an item to aid in her travels. The pants suggestion though omg haha very true also.